Tag Archives: flu

Scientists are ‘encouraged’ by advanced universal flu vaccine

Credit: pixabay.

As 2020 draws near to a close, it’s quite clear that the world was not ready for a pandemic — but hopefully, we will avert those that may follow. Influenza viruses have been responsible for many pandemics in the past, including the devastating 1918 Spanish flu that killed 50 million people worldwide. But a universal flu vaccine developed by researchers at Mount Sinai Hospital could stop a future influenza outbreak dead in its tracks before it gets the chance to develop into a pandemic.

There are quite a few strains of influenza circulating among people that cause seasonal flu, which is responsible for about 650,000 deaths every year globally. In order to prevent infection, people can get vaccinated but the problem is that there are not only different flu viruses circulating, but viruses can also mutate. If antibodies from a previous infection or vaccine meet a virus whose surface structure they don’t recognize, then those receptors don’t match and they cannot block it.

This is why we have to take a flu vaccine every year — and they’re not perfect. These vaccines contain three or four strains of the influenza virus, which public health experts predict will be circulating in the subsequent season. The problem is that sometimes these predictions don’t match the reality in the field, with different strains actually circulating among the population.

For years, scientists have been working on a universal vaccine that would both offer protection against multiple known strains of influenza and prime the body against new outbreaks. Of course, that’s easier said than done, but a vaccine developed at Mount Sinai Hospital in New York City may be the most promising one so far.

The chimeric hemagglutinin (HA)-based vaccine targets different parts of the hemagglutinin protein, the major surface glycoprotein of the influenza virus that binds to host cell receptors.

“An influenza virus vaccine that results in broad immunity would likely protect against any emerging influenza virus subtype or strain and would significantly enhance our pandemic preparedness, avoiding future problems with influenza pandemics as we see them now with COVID-19” says Florian Krammer, Professor of microbiology at the Icahn School of Medicine at Mount Sinai, and corresponding author of the study.

“Our chimeric hemagglutinin vaccine is a major advance over conventional vaccines which are often mismatched to the circulating strains of virus, impacting their effectiveness. In addition, revaccinating individuals annually is a huge and expensive undertaking.”

Conventional vaccines produce neutralizing antibodies by targeting a part of the hemagglutinin, known as the globular head domain. The problem is that mutations help the virus escape neutralization through a process known as “antigenic drift”, according to Peter Palese, professor of microbiology and chair of the Department of Microbiology at Icahn School of Medicine at Mount Sinai, and co-author of the study.

“This genetic change, or shift, in the virus results in immunity to only specific strains of the influenza virus, requiring frequent re-formulation and re-administration of seasonal vaccines. Our chimeric HA vaccine, by contrast, is directed at the proximal part of the HA protein — the stalk domain — which has been shown to broadly neutralize diverse influenza virus strains in both animal models and humans,” he added.

Such a vaccine not only offers broad protection but is also multifunctional, in the sense that the antibodies it induces can neutralize many kinds of influenza viruses.

For countries that lack an advanced medical infrastructure and the resources to vaccinate their population every year, a universal vaccine would be extremely appealing. Most importantly, as this pandemic has shown, we need robust tools at our disposal in order to nip potential devastating outbreaks in the bud.

Of course, safety is first. In a phase 1 clinical trial that involved 65 participants in the United States, the researchers found that the vaccine produced a strong immune response that was still viable 18 months after vaccination.

“This phase of our clinical work significantly advances our understanding of the immune response in terms of its longevity,” said Dr. Krammer, “and leaves us greatly encouraged about future progress for this potentially breakthrough vaccine.”

The findings appeared in the journal Nature Medicine.

How long are you contagious with a cold or flu?

Credit: Pixabay.

With the COVID-19 pandemic still sweeping the world, it’s easy to forget about the annoying, yet far more benign viral infections that plagued us thus far.

The flu and the common cold are some of the most common respiratory infections. Both are caused by highly infectious viruses, although from different families of viruses.

The common cold is caused by over 200 different viruses. About 30-35% of all adult colds are caused by rhinoviruses, but some cases are also caused by a handful of coronaviruses, the older cousins of the virus that causes COVID-19. This huge diversity of viruses is one of the reasons why we don’t yet have a universal vaccine for the common cold.

Meanwhile, the flu is caused by only a couple of influenza viruses, enabling researchers to develop new vaccines every year to neutralize new mutations and keep seasonal outbreaks at bay.

How long are you contagious with the flu?

The typical incubation period for influenza is one to four days, meaning it takes about that much time for symptoms to show after the initial infection. However, people can pass on the illness to others a day before the onset of symptoms and up to seven days after symptoms first show. The most infectious period is 3 to 4 days after you start feeling sick.

Children and adults with poor immune systems may be infectious for a few days longer.

Like most respiratory viruses, influenza is spread through direct contact, from one person to another. This can happen when an infected person sneezes or coughs into the air and then a susceptible host comes in contact with these viral-loaded droplets of moisture.

In order to protect co-workers and school colleagues, Dr. William C. Wilson, who is the chief medical officer of the University of California Irvine Health, recommends you make sure you check all item on this list to be on the safe side:

  • No fever for 24 hours — without fever-reducing medications
  • No vomiting or diarrhea for at least 24 hours
  • Coughing or sneezing should be reduced and intermittent

How long are you contagious with the common cold?

People sick with the common cold will be contagious for much longer than is the case for the flu. While people sick with the flu will generally stop being contagious after a week, those sick with the common cold may be contagious for up to three weeks.

It depends a lot on the kind of virus involved. If the common cold symptoms are caused by a rotavirus, you can spread it to others even before you develop symptoms — and up to two weeks after you’ve recovered.

Generally speaking, you’ll be contagious 1-2 days before the onset of symptoms and for up to 2 weeks. You’re more likely to infect others during the first few days, when symptoms are at their worst.

After common cold symptoms fade away, you should still wait 24-36 hours before returning to your normal work or work schedule.

How do I know if I have the cold or the flu?

Many symptoms for both types of viral infections overlap, such as cough, runny nose, and feeling tired, which can make it challenging to tell the difference between the two.

Colds come on gradually over a few days and are often milder than the flu. They usually get better in 7 to 10 days, although symptoms can last for up to 2 weeks.

Flu symptoms come on quickly — often within 1 to 3 days — and can be severe. Basically, if you wake up one morning suddenly feeling like you’ve been hit by a truck, it’s likely the flu. Symptoms usually last 1 to 2 weeks.

Influenza is responsible for head and body aches, whereas cold aches are much milder.

With a cold, you may or may not feel tired. With the flu, however, tiredness and weakness are common.

Some people get a slight fever when struck by a cold, but most don’t. In contrast, any fever above 38 degrees Celsius (101 to 104 degrees Fahrenheit) is a sign of the flu, with children’s fevers tending to be higher.

Tips for returning to work after being ill with the flu or common cold

If you’ve gained at least 90% of your energy back and overall symptoms are gone or decreased significantly, it may be safe to return to work or engage in social activities. When you do return, remember:

  • Wash your hands frequently and sanitize any surfaces such as computer keyboards and telephone handsets and receivers.
  • Protect your coworkers by avoiding those with weakened immune systems.
  • If you are still coughing or sneezing, wear a medical mask to prevent the spread of virus-filled droplets.
  • Sneeze or cough into a tissue or into the bend of your elbow — not your hand — to keep droplets from spreading.
  • Ease back into your work pace to allow your body to recover fully and to prevent yourself from relapsing back into illness.

Another positive effect of coronavirus restrictions: flu outbreaks are massively down

Lockdowns, masks, and distancing are saving lives in more ways than one: in the southern hemisphere winter, the spread of flu is at remarkably low levels.

“I think if we could get this sort of effect every year, we’d be very happy,” said Professor Ian Barr, deputy director of the World Health Organization Collaborating Centre for Reference and Research on Influenza.

Influenza is hard to combat, but it almost disappeared

It’s one of the fears we’ve had with COVID-19 from the start: when winter comes and we add the pandemic to the higher winter health burden, it will be a disaster. But as it turns out, we get a 2-for-1 offer with the coronavirus restrictions.

It’s wintertime in the southern hemisphere, and it’s exactly the time when the flu starts to flare up.

The flu is a nuisance to most people, but it’s also a very threatening disease in its own right. In the severe flu season 2017-2018, health officials estimate that 900,000 Americans were hospitalized, and on average, the flu kills 30,000 people in the US every year. Worldwide, it’s estimated that the flu kills over 600,000 people every year — while not as severe as COVID-19, the flu is no laughing matter.

Luckily, it turns out that the measures aimed at containing and halting the spread of COVID-19 also help with the flu.

We’re seeing this already in several countries. Australian Medical Association NSW vice-president Andrew Zuschmann said this year doctors are already seeing much lower transmission rates of influenza than in previous years.

“What it’s telling us is that many of the measures that are working to contain the spread of COVID-19 within the community are also very effective at reducing transmission of influenza,” he said.

All across the Southern hemisphere, officials were bracing for a wave of flu on top of the ravaging coronavirus — but the wave of flu never came. In the latter half of June, Australia registered only 85 lab-confirmed influenza cases — compared to 22,047 for the same period in 2019. In Chile, Cases have dropped to 1,100 this season, compared to 210,000 last year. In Argentina, cases have also decreased from over 4 million to 151,000.

Speaking with the Wall Street Journal, Chilean infectious-disease specialist Claudia Cortés says the flu has almost disappeared.

“We keep checking for the other viruses, but all we’re seeing is Covid,” said Dr. Cortés, the Chilean doctor. Of roughly 1,300 Covid-19 patients she has treated since late March, only a handful had the flu. “We were surprised by the decline in the other viruses like influenza. We never dreamed it would practically disappear,” she said.

Similar things are being reported all across the southern hemisphere: even during peak flu season, the numbers are still very low.

Now we know how to combat influenza

The decline is good news for health officials all around the planet, especially when winter also comes in the northern hemisphere.

This improvement is largely attributed to protective measures against COVID-19. Whether it’s face masks, distancing, or things being shut down, everything that reduces COVID-19 transmission also helps with the flu.

Kids are also an important transmission route for the flu. As many countries closed down schools, this also helped with the flu.

While this is all encouraging, there’s also a concerning takeaway. This all seems to suggest that flu and COVID-19 move in tandem, but even as the flu has all but disappeared from South America, COVID-19 is soaring. This suggests that the novel coronavirus is much more contagious than the flu viruses, and even as the flu is tamed in wintertime, dealing with COVID-19 is an entirely different problem.

The northern hemisphere is not doing a great job with the pandemic in the summertime. Cases are surging across the US and parts of Asia, and even parts of Europe which seemed to have things under control a few weeks ago, are reporting concerning developments.

The flu situation is good news, and it offers a glimmer of hope for wintertime — but there’s still a long way to go to wintertime.

Scientists are working on a biosensor that detects COVID-19 and the flu at the same time

This sensor is the size of a micro USB drive and is capable of testing for influenza and COVID-19 simultaneously. Credit: Dmitry Kireev, University of Texas at Austin.

We’ve said it before, and we’re saying it again now: COVID-19 is much more dangerous than the flu. However, the two viral infections share some symptoms, such as fever and cough. In anticipation of the upcoming flu season in autumn and winter, researchers at the University of Texas are now working on a sensor that can differentiate between the two types of viruses from a single sample.

Having the flu during the pandemic can be confusing and downright scary since some of the symptoms overlap. Do you quarantine yourself because you’re not sure what’s going on? Do you go straight to the hospital to get a test, where you might actually risk contracting a coronavirus infection?

Researchers at the University of Texas are working on a dual test that might dispel such concerns, potentially saving millions in tax dollars and many man-hours for medical personnel.

“With a second wave of the coronavirus likely to appear right as we get into flu season, there’s an urgent need for diagnostics that can differentiate between COVID-19 and influenza,” said Deji Akinwande, a professor in the Cockrell School of Engineering’s Department of Electrical and Computer Engineering.

Previously, Akinwande and colleagues created a graphene-based biosensor that accurately detects iron deficiency in children. Graphene, the atom-thick sheet of carbon arranged in a honeycomb-shaped lattice, is very sensitive to charged particles. When combined with anti-ferritin antibodies, the biosensor becomes reactive to that one biomolecule.

Graphene is so sensitive that it can even detect tiny biomolecules, such as viruses.

“It became clear that just by changing the antibody, we could pivot the platform to focus on the coronavirus,” Akinwande said.

The dual test would be infused with antibodies of both the coronavirus and influenza, with one side being sensitive to COVID-19, while the other side reacts only to the flu.

The sensor, which is no larger than a micro USB drive, would save precious resources and save time for medical personnel. It would also reduce the usage of nasal swabs, currently in short supply.

Although there have been no sanctioned experiments yet, the research team plans on initially using inactive samples of coronavirus and influenza for their first tests. These early results will determine how well the sensor can connect to the coronavirus’ spike protein, which it uses to bind to human cells and cause infection.

If the prototype is proven effective, mass production will be ramped up as soon as the researchers find a suitable partner. For now, the dual test is supported by a grant from the National Science Foundation.

The more we look at COVID-19, the less it looks like the flu

If you went back in time to a month ago, you’d probably find many people wondering whether COVID-19 is worse than the flu. There’s no excuse for believing that now.

It’s hard to imagine that New York’s current situation, where it feels like “every day is 9/11”, is better than what most scenarios depicted. It truly is the challenge of a generation, and while the flu is also a major health burden in itself, this is nothing like the flu.

Initially, the case fatality rate reported in Wuhan, China, was around 2%. That was already much higher than the fatality rate of influenza, which is around 0.01% – 0.1%. Now, if we look at official numbers, it would seem that the case fatality rate is closer to 10% — this is the case in places like Italy, the UK, or New York. In reality, many more infected people aren’t being tested, so the real number of infections is much higher than the official one, which, in turn, brings the overall fatality rate lower.

But no matter how we look at it, it’s very different from the flu.

In New York, COVID-19 has already claimed more lives than the last five years of influenza put together, and it’s only been a couple of weeks since the outbreak started in the state — and that’s with a major lockdown, with drastic quarantine measures, with doctors coming out of retirement, and with the most concentrated health effort in modern history. It’s hard to imagine how the chart above would have looked if we all continued business as usual.

The problem is that this idea that “it’s just a flu”, that it’s nothing major, significantly slowed down containment measures. Even as the virus was surging through New York City, dozens of articles and photos showed New Yorkers taking to the parks and paying little attention to social distancing.

Now, the city’s municipality is burying unclaimed bodies in Potter’s Field on Hart Island.

The good news is that the COVID-19 epidemic in New York may be nearing its peak. The bad news is that as bad as it is, this is probably just the first wave — and things need to be managed carefully after this wave to ensure that the second wave isn’t even more devastating.

Much of this could have been avoided by an earlier response, and if more people had taken the disease more seriously. Similarly, much of the damage COVID-19 might cause in the future can be alleviated if we take it seriously and take individual precautions.

For the last time, it’s not the damn flu.

Your resistance to flu is shaped by previous flu’s, and their type

How hard the flu hits us has a lot to do with our first experience of the disease, a new paper reports.

Image via Pixabay.

Researchers at the University of California Los Angeles (UCLA) and the University of Arizona may finally have an explanation as to why different people seem to have such different reactions to the flu. And, to a large extent, they report, it has to do with your childhood.

Early experience

“Our immune system often struggles to recognize and defend against closely related strains of seasonal flu, even though these are essentially the genetic sisters and brothers of strains that circulated just a few years ago,” said lead author Katelyn Gostic, currently a postdoctoral fellow at the University of Chicago.

“This is perplexing because our research on bird flu shows that deep in our immune memory, we have some ability to recognize and defend against the distantly related, genetic third cousins of the strains we saw as children.

An individual’s ability to fight off the flu is related to the number of different flu strains they contracted during their lifetime and the order in which they did so. Prior exposure to a pathogen, be it in the wild or controlled (in a vaccine) is known as immunological imprinting.

For the study, the team set out to determine whether immunological imprinting could explain differences in how people respond to the flu. They used health records from the rizona Department of Health Services to track how different varieties of the virus affect people at various ages, focusing on the H3N2 and H1N1 strains. These strains were selected as both have led to seasonal outbreaks over the past few decades, so there was enough data on them to work from.

In very broad lines, H3N2 is more closely associated with severe flu cases in elderly people and causes the majority of flu-related deaths. H1N1 seems more partial to children and young adults and is far less deadly.

The data showed that people who were first exposed to H1N1 during childhood were less likely to require hospitalization if they re-encountered the strain later on in life compared to those who were first infected with H3N2. Similarly, this latter group would be more resistant to subsequent reinfections of H3N2.

The team looked at the evolutionary relationship between the two strains and report that they belong to two different branches of the influenza family. Further research revealed that while infection with any of the strains does somewhat boost resistance against any other, the best effects are seen with strains from the same family that an individual has battled before. Furthermore, your first exposure seems to grant you extra protection against related strains in the future: people who had their first run-in with flu as children in 1955 (N1H1 strain) were significantly more likely to be hospitalized with an H3N2 infection than an H1N1 infection when both strains were circulating.

However, the team also found that people whose first childhood exposure was to H2N2 did not have better protection when they later encountered H1N1 (although the two strains are closely related). They are still unsure as to why this is.

“We hope that by studying differences in immunity against bird flus — where our immune system shows a natural ability to deploy broadly effective protection — and against seasonal flus — where our immune system seems to have bigger blind spots — we can uncover clues useful to universal influenza vaccine development.”

The paper “Childhood immune imprinting to influenza A shapes birth year-specific risk during seasonal H1N1 and H3N2 epidemics” has been published in the journal PLOS Pathogens.

Diabetes rising worldwide: one in 11 adults affected

Diabetes is one of the world’s fastest growing chronic diseases with over 463 million adults (that’s 1 in 11 adults) around the world living with this chronic medical condition according to new data published in the 9th Edition of the International Diabetes Federation (IDF) Diabetes Atlas. The latest Atlas also reports that the global prevalence of diabetes has reached 9.3%, with more than half (50.1%) of adults undiagnosed. A further 1.1 million children and adolescents under the age of 20, live with type 1 diabetes.

A decade ago, in 2010, the global projection for diabetes in 2025 was 438 million. With over five years still to go, that prediction has already been surpassed by 25 million. IDF estimates that there will be 578 million adults with diabetes by 2030, and 700 million by 2045.

Diabetes itself is not a major problem unless the blood glucose is uncontrolled and either rises too high or drops too low. If diabetes is not managed correctly (meaning blood glucose is not properly regulated), sufferers are likely to become progressively sick and debilitated.

Over time, diabetes can damage the heart, blood vessels, kidneys, eyes and nerves. For diabetics, maintaining blood sugar levels in a normal range — not too high or too low — is a lifelong challenge. Half of the people with diabetes die of cardiovascular disease (primarily heart disease and stroke), and 10–20 percent of people with diabetes die of kidney failure. Diabetes is also a major cause of blindness and lower limb amputation.

IDF estimates that approximately 4.2 million adults will die as a result of diabetes and its complications in 2019. This is equivalent to one death every eight seconds.

Flu season is quickly approaching and patients with diabetes are particularly at high risk of serious flu-related complications that can result in hospitalization or even death. Diabetics are twice as likely to die from heart disease or stroke as people without diabetes and six times more likely to be hospitalized. 

Flu infection can cause changes in blood sugar and prevent people with diabetes from eating properly, which further affects blood glucose. Moreover, diabetes can make the immune system less able to fight infections. Diabetes patients with flu face very serious health risks such as ketoacidosis (a condition when the body cannot use sugar as a fuel source because there is no insulin or not enough insulin) and Hyperosmolar Hyperglycaemic State (HHS).

It is important for people with diabetes to follow the sick day guidelines if they become ill. Flu vaccination is especially important for people with diabetes because they are at high risk of developing serious flu complications. Flu vaccination has also been associated with reduced hospitalizations among people with diabetes (79%). Diabetics who get the flu should ask their doctors about prescription antiviral medications that can ease symptoms and shorten the duration of the illness. For best results, antivirals should be taken within 48 hours of the onset of flu symptoms.

Medical masks as good as respirators against the flu, viruses

It pays to have a medical mask on hand during flu season.

Image credits Paul Keller / Flickr.

New research reports finding “no significant difference in the effectiveness” of medical masks vs. N95 respirators for prevention of influenza or other viral respiratory illness.

One dime mask

“This study showed there is no difference in incidence of viral respiratory transmission among health care workers wearing the two types of protection,” said Dr. Trish Perl, Chief of UT Southwestern’s Division of Infectious Diseases and Geographic Medicine and the report’s senior author.

“This finding is important from a public policy standpoint because it informs about what should be recommended and what kind of protective apparel should be kept available for outbreaks.”

Nurses, doctors, and other medical personnel who come into direct contact with patients are frequently exposed to contagious diseases such as influenza (flu). During large outbreaks (such as the H1N1 pandemic of 2009) as many as one in three healthcare workers could contract the disease they’re fighting against, says Dr. Perl.

During that pandemic, the U.S. Centers for Disease Control and Prevention (CDC) recommended the use of N95 respirators, designed to fit closely over the nose and mouth and filter at least 95% of airborne particles. The looser-fitting surgical masks routinely worn by healthcare workers were considered insufficient, Dr. Perl said, but there weren’t enough of N95 filters for every facility.

The new study came to follow-up on previous research comparing the masks and respirators, which yielded mixed results. The team used data from several Department of Veterans Affairs hospitals and multiple medical institutions in seven cities including Houston, Denver, Washington, and New York, collected with the help of multiple universities throughout the USA. The figures pertained to the four flu seasons between 2011 and 2015, examining the incidence of flu and acute respiratory illnesses in the almost 2,400 health care workers who completed the study.

The team reports that 207 laboratory-confirmed influenza infections occurred in the N95 groups versus 193 among medical mask wearers. In addition, they found 2,734 cases of influenza-like symptoms, laboratory-confirmed respiratory illnesses, and acute or laboratory-detected respiratory infections (where the worker may not have felt ill) in the N95 groups, compared with 3,039 such events among medical mask wearers.

“It was a huge and important study — the largest ever done on this issue in North America,” says Dr. Perl.

“The takeaway is that […] one type of protective equipment is not superior to the other,” she adds. “Facilities have several options to provide protection to their staff — which include surgical masks — and can feel that staff are protected from seasonal influenza. Our study supports that in the outpatient setting there was no difference between the tested protections.”

The team plans to investigate the dynamics of virus transmission in the future, in order to better understand how to protect medical personnel from them.

The paper “N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel” has been published in the journal JAMA.


Researchers make chicken cells resist bird flu by snipping out a tiny bit of their DNA

Designer chicken cells grown in the lab at Imperial College London can resist the spread of bird flu.


Image credits Samet Uçaner.

Bird flu, as its name suggests, is mostly concerned with infecting birds. And it’s quite good at it: severe strains of bird flu can completely wipe out a whole flock. In rare cases, the virus can even mutate to infect humans, causing serious illness. As such, bird flu is a well-known and scary pathogen in the public’s eye.

Now, researchers from Imperial College London and the University of Edinburgh’s Roslin Institute have devised chicken cells that can resist infection with the bird flu virus. Their efforts pave the way towards effective control of the disease, safeguarding one of the most important domesticated animals of today.

Be-gone, flu

“We have long known that chickens are a reservoir for flu viruses that might spark the next pandemic. In this research, we have identified the smallest possible genetic change we can make to chickens that can help to stop the virus taking hold,” says Professor Wendy Barclay, Chair in Influenza Virology at Imperial College London and the paper’s corresponding author. “This has the potential to stop the next flu pandemic at its source.”

The findings could make it possible to immunize chickens to the virus using a simple genetic modification. No such chickens have been produced just yet, but the team is confident that their method will prove safe, effective, and palatable with the public in the long run.

The approach involves a specific molecule found in chicken cells, called ANP32A. Researchers at Imperial report that during a bird flu infection, viruses use this molecule to replicate (multiply) and continue attacking the host. The researchers from the University of Edinburgh’s Roslin Institute worked to gene-edit chicken cells to remove a portion of DNA that encodes the production of ANP32A.

With this little tweak, the team reports, the virus was no longer able to replicate inside the cells.

Members at The Roslin Institute have previously worked on something similar. Teaming up with researchers from Cambridge University at the time, they successfully produced gene-edited chickens that didn’t transmit bird flu to other chickens following infection. However, the approach they used at the time involved adding new genetic sequences into the birds’ DNA; while the proof-of-concept was very encouraging, the approach didn’t seem to stick, commercially.

“This is an important advance that suggests we may be able to use gene-editing techniques to produce chickens that are resistant to bird flu,” says Dr. Mike McGrew, of the University of Edinburgh’s Roslin Institute and a paper co-author.

“We haven’t produced any birds yet and we need to check if the DNA change has any other effects on the bird cells before we can take this next step.”

The paper “Species specific differences in use of ANP32 proteins by influenza A virus” has been published in the journal eLife.

Why are people more likely to get sick or die from flu during winter months?

In the temperate regions, between the subtropics and the polar circles, temperatures are not “extreme”, not burning hot nor freezing cold (temperate means moderate). In these parts of the world, seasonal influenza virus outbreaks happen during the winter months — peaking between November and March in the Northern Hemisphere (i.e. All of continental Europe, North America) and between May and September in the Southern Hemisphere (i.e. Australia, Zealandia, Brazil).

Scientists have hypothesized several reasons for this. Maybe because people are inside more in cold weather, one theory holds, so the virus spreads more easily. Or maybe it’s because people are not out in the sun making Vitamin D, and their immune systems are weak. Or perhaps people travel for holidays at certain times of years, helping spread the virus. So far, not one of these theories has proved a winner.

Recently, a group of researchers from Yale University, Veterans Affairs Connecticut Healthcare System, and Howard Hughes Medical Institute has pinpointed a key reason why people are more likely to get sick and even die from flu during winter months: low humidity.

The Yale research team, led by Akiko Iwasaki, the Waldemar Von Zedtwitz Professor of Immunobiology, explored the question using mice genetically modified to resist viral infection like humans do. The mice were all housed in chambers at the same temperature, but with either low or normal humidity. They were then exposed to the influenza A virus. The study was published in the Proceedings of the National Academy of Sciences (PNAS).


They found that low humidity hindered the immune response of the animals in three distinct ways: 1) it prevented cilia, which are hair-like structures in airways cells, from removing viral particles and mucus, 2) it also reduced the ability of airway cells to repair damage caused by the virus in the lungs, 3) in low humidity, interferons or signaling proteins released by virus-infected cells to alert neighboring cells to the viral threat do not function optimally. The study offers insight into why the flu is more prevalent when the air is dry.

“It’s well known that where humidity drops, a spike in flu incidence and mortality occurs. If our findings in mice hold up in humans, our study provides a possible mechanism underlying this seasonal nature of flu disease,” said Akiko Iwasaki.

While the researchers emphasized that humidity is not the only factor in flu outbreaks, it is an important one that should be considered during the winter season. Increasing water vapor in the air with humidifiers at home, school, work, and even hospital environments is a potential strategy to reduce flu symptoms and speed recovery, they said. In addition, it’s always a good idea to wash your hands often and get vaccinated with the flu vaccine.

More evidence showing that flu vaccination lowers risk of death in heart failure patients

Credit: Pixabay.

Patients diagnosed as having heart failure had an 18% lower risk of death if they subsequently received the seasonal influenza vaccine, according to a recent study published in Circulation, a journal of the American Heart Association (AHA).

The flu season is an annually recurring time period characterized by the prevalence of outbreaks influenza that occurs during the cold half of the year in each hemisphere. It usually starts late fall and runs through the spring, with flu cases peaking during the winter months.

Influenza can be very serious or even fatal for patients with heart failure because these patients are often older than 65, have other health complications, and infection exacerbates heart failure symptoms. Heart failure is expected to increase over the next decades as the world’s population ages and people live longer.  By 2050, the world’s population aged 60 years and older is expected to total 2 billion, up from 900 million in 2015.

Some people are at higher risk for serious flu complications, including young children, older people, pregnant women and people with certain chronic health conditions.

In this study, researchers analyzed data on 134,048 heart failure patients over a 12-year period from 2003 to 2015. After adjusting for income, co-morbidities, and other factors, the researchers found the following:

  • Flu vaccination was associated with an 18% reduced risk of premature death. Annual flu vaccination following a heart failure diagnosis was associated with a 19% reduction in both all-cause and cardiovascular death when compared with no vaccination.
  • Frequency of flu vaccination mattered — getting a flu vaccine less than once per year but more than not at all was associated with a 13% reduced risk of all-cause death and an 8% reduced risk of cardiovascular death.
  • Timing also mattered — there was a greater reduction in cardiovascular and all-cause death when vaccination occurred earlier in the flu season.

According to study lead author Daniel Modin of the University of Copenhagen, while their research only looked at patients with newly diagnosed heart failure, the protection from a flu vaccination likely benefits any patient with heart failure. The research team hopes the study can help in making physicians and cardiologists aware of how important flu vaccines are for their patients.

An earlier publication from 2013 analyzed six studies dating back to the 1940s concerning the heart health of over 6,700 men and women with an average age of 67. About a third had heart disease and the rest had risk factors such as high cholesterol, high blood pressure, and diabetes. They found that people who had received the flu vaccine were: 36% less likely to experience heart disease, stroke, heart failure or death from cardiac-related causes and 55% less likely to suffer a cardiac event if they had recently experienced a heart attack or stroke.

Several other studies have concluded that flu vaccination should be considered as an integral part of chronic heart diseases management and prevention. While the European Society of Cardiology, American College of Cardiology, American Heart Association, cardiology experts & many other health organizations recommend flu vaccines for patients with heart disease, rates of vaccination in these groups are low.

Homeopathy is ineffective against children’s cold and flu

Add another one to the pile: a new review of randomized controlled trials on the common cold, influenza, and pneumonia found no evidence that homeopathy is effective in any way.

Homeopathy doesn’t work, and according to everything we know about science — it can’t work.

If it’s your first time on ZME Science — first of all, welcome — there’s one thing you should know about us: we love science — and like everyone who loves something, we hate it when something else masquerades as that something we love. In this case, we’re talking about pseudoscience.

Sure, you can argue that most (if not all) people believe in something illogical. Most of the time, that doesn’t do any harm — after all, what difference does it make if you read the daily horoscope or not? But some beliefs are more dangerous than others, especially when it comes to medical science. Obviously, medicine isn’t perfect and there’s still a lot of room for improvement but thanks to medical science, we live longer and healthier than all the generations before us. So why, then, would you doubt and reject it?

Homeopathy goes against everything we know about chemistry, biology, and medicine. It’s completely implausible from a theoretical standpoint, and study after study has shown that the practical effects just aren’t there. It might seem like it works (and here’s why), but the data suggests otherwise.

In a new study published in the prestigious Cochrane Database of Systematic Reviews, a team of researchers looked at how good homeopathy is in dealing with the cold, the flu, and pneumonia.

Common homeopathic ‘treatments’ for these conditions include Arsenicum album (arsenic trioxide), Euphrasia (eyebright plant), and natrum muriaticum (or as most people call it, table salt). A particular flu remedy called Oscillococcinum is derived from duck liver and heart. If that’s not enough to dissuade you, then the preparation mechanism likely will.

Homeopathic substances are heavily diluted in water, often times by a factor of a trillion or even more. Sometimes, they’re diluted so much that not a single molecule of the original substance remains — by everything we know about chemistry, there’s nothing but water left in these substances. Supposedly, this dilution makes substances stronger — which again, goes again everything we know about physics.

The researchers scoured the literature to find any studies comparing oral homeopathy medicinal products with identical placebo or self‐selected conventional treatments. They found eight such studies, and this is where it gets interesting.

Researchers did find eight suitable studies. A few of these studies did suggest some benefits, and at a quick glance, you’d say that it’s good enough — it’s published in a journal, it passed the test of peer-review, so why not? But when researchers looked closer, they found all sorts of problems, ranging from major inconsistencies to a blatant conflict of interest — three of the studies were directly funded by homeopathy manufacturers. In these studies, even the reviewers were dubious of their claims.

“One study showed a reduction in disease severity for the homeopathy group at some time points. The other study showed a reduction in number of respiratory infections over the following year in the treatment groups, although more than a quarter of participants were not accounted for in the results,” the reviewers wrote.

Meanwhile, the more rigorous studies consistently find no benefits to homeopathy. The authors give a stern conclusion:

“There is no convincing evidence homeopathic medicinal products are effective in treating ARTIs in children.”

Intriguingly, advocates of homeopathy often claim that it’s a “true” healing practice, unlike modern medicine, which is “all about the money.” However, these people conveniently disregard the fact that in the US alone, homeopathic and herbal remedies are a multi-billion dollar industry.

When you draw the line, homeopathy doesn’t work, it even can’t work (based on pretty much everything we know about science), and still it makes a lot of money. So why is it still a thing? It’s hard to say, but as always, we encourage you to leave your opinion in the comment section.

When it comes to influenza — Men Are from Mars, Women Are from Venus

Flu vaccine seems more effective in women; men recover faster from the flu.

Influenza (also known as the flu) is the smartest virus on the planet. Every year, seasonal influenza kills up to 650,000 people in the world, but when the flu season is over, people usually forget about the hundreds (or even thousands) who died and how bad the past flu season was. Until scientists create something more effective, the flu shot is still the best way to protect yourself and your family from flu and any associated illness. But no matter how often people are reminded to get the vaccine, and how often healthcare professionals tell patients compelling reasons to get vaccinated, flu shots are always a hard sell.

Scientists conduct studies each year to determine how well the influenza (flu) vaccine protects against flu illness. While vaccine effectiveness can vary, studies show that flu vaccination reduces the risk of flu illness by between 40% and 60% during seasons when most circulating flu viruses are well-matched to the flu vaccine. The vaccine’s effectiveness can also vary depending on the characteristics of the person being vaccinated (such as their age and health), and the similarity or “match” between the flu strains included in the vaccine and the flu viruses spreading in the community. However, gender appears to have a significant impact on the efficacy of the influenza vaccine as well according to a study entitled “Should sex be considered as an effect modifier in the evaluation of influenza vaccine effectiveness?” published in Open Forum Infectious Diseases.

It has long been known that gender can correlate with health with influenza. For example, women have increased exposure to influenza due to historical gender norms under which more women serve as primary caregivers than men. Nevertheless, men, although exposed less to the flu, tend to have higher rates of mortality and morbidity from the flu. Women are also more likely to be vaccinated than men, and they tend to seek health care more quickly when they are sick.

Colorized transmission electron micrograph showing H1N1 influenza virus particles. Surface proteins on the virus particles are shown in black. Credit: NIAID, Flickr.

Colorized transmission electron micrograph showing H1N1 influenza virus particles. Surface proteins on the virus particles are shown in black. Credit: NIAID, Flickr.

Investigators in this study wanted to ascertain the extent to which gender itself—not just cultural and behavioral norms around gender— could affect the effectiveness of the flu vaccine. To study the question, the investigators looked at a database of patients over seven flu seasons, from 2010-2011 to 2016-2017. Patients were included if they were at least 1-year-old and had seen a doctor within seven days of the onset of flu-like symptoms. Vaccination status was recorded based on patient self-reports and only those who had been given the flu shot at least two weeks before the diagnosis of flu were included in the study.

Results showed that women were less likely than men (43% versus 40%) to end up with a positive flu test and were more likely (29% versus 23%) to have received the flu shot. The overall vaccine effectiveness for women was considerably higher (49% versus only 38% for men). The difference in effectiveness varied by strain with the greatest dissimilarity in the A (H3N2) and B (Victoria) strains. Among patients not given the flu vaccine, there was no gender-based difference in influenza infection rates.

The authors wrote that “…these findings suggest that biological gender differences in response to the vaccine, rather than gender differences in health care seeking or vaccination status reporting, likely explains the observed differences in influenza VE between males and females.” In addition, the authors noted that previous research has suggested women have “stronger innate and adaptive immune responses, including more pronounced antibody response to influenza vaccine, in association with higher rates of local and systemic adverse events following immunization.”

Credit: Air Force District of Washington.

Credit: Air Force District of Washington.

Another possible biological cause for the difference in vaccine effectiveness is that testosterone can be immunosuppressive at high levels. The gender-based difference in vaccine effectiveness gap was most obvious among older adults (potentially because of age-related immune system changes or immunosenescence) and prepubescent children. According to corresponding author Danuta Skowronski MD, FRCPC, of the British Columbia Centre for Disease Control, if the findings are confirmed, one day physicians and vaccine developers might consider gender when developing newer influenza vaccines and flu prevention strategies.

This comes after the publication by scientists at Johns Hopkins Bloomberg School of Public Health in the journal Biology of Sex Differences showing that a protein called amphiregulin (AREG) could be the reason why men recover from influenza more quickly than women. AREG is an Epidermal Growth Factor (EGF)-like molecule that plays a critical role in wound and tissue healing following infection or injury.

Certainly, more evidence is needed before public health experts can say whether influenza prevention strategies should vary by gender or whether a gender-specific influenza prevention strategy is warranted. But for now we know that flu vaccine effectiveness seems to be higher in women but men seem to recover faster from the influenza infection.

Obesity May Also Increase Flu Spread, Not Just Flu Severity

Credit: Pixabay.

Obesity and overweight

Overweight and obesity are conditions where a person has accumulated an excessive amount of fat that may impair their health. A simple index used to classify overweight and obesity is the body mass index (BMI), which is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2). To learn more about obesity, BMI and how it is measured, check this information page from the World Obesity Foundation and the video below.

Obesity and diseases

A high BMI is a major risk factor for non-communicable diseases such as cardiovascular diseases (mainly heart disease and stroke), diabetes, musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints), and some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon). The risk of these non-communicable diseases rises with increases in BMI.

Obesity and infections

Available data suggest that obese people are more likely than people of normal weight to develop infections of various types including postoperative infections (infections after surgical procedures) and other nosocomial infections (infections that are acquired in a hospital or other healthcare facility). Scientists already know that obesity increases a person’s risk of suffering from severe complications from influenza. Previous epidemiologic studies in Morbidity and Mortality Weekly Report and PLoS Medicine showed an association between obesity and severe complications and death from influenza, especially in the elderly. However, recently researchers who studied households in Managua, Nicaragua over three flu seasons found that it takes obese adults about 1.5 times longer to shed the virus than non-obese adults. This was published in the Journal of Infectious Diseases (JID).

Obesity and flu transmission

Dr. Aubree Gordon from University of Michigan School of Public Health, a senior study co-author, said in a press release from the Infectious Diseases Society of America (IDSA) that the findings are the first real evidence that obesity might affect more than just disease severity; “it might directly impact transmission as well.”

Flu vs cold

Credit: Pixabay / Sambeet.

The researchers monitored two groups including 1,783 people from 320 households during three flu seasons from 2015 to 2017. Among the group, 87 were infected with influenza A while 58 were sickened by influenza B. It took obese adults with two or more symptoms 42% longer to shed the influenza virus compared to adults who were not obese. Moreover, obese adults who had no symptoms or had milder infections shed the virus for 104% longer. However, obesity did not increase viral shedding in children ages 5 to 17 or for adults who had influenza B illness.

The researchers cannot say for sure how obesity could extend viral shedding in those with flu; however, it is a known fact that obesity alters the immune system and can lead to chronic inflammation, which also increases with age. The researchers also note that obesity can make breathing more difficult and increase the need for oxygen. They also suggest that chronic inflammation triggered by obesity could be responsible for increased shedding of influenza A. Reducing obesity rates can have the benefit of limiting the spread of viral diseases, the authors said. Further research is needed to determine whether the flu virus shed over longer periods by obese patients is infectious and if it is able to infect others.

A commentary on the study was included in the same JID issue by Dr. Stacey Schultz-Cherry of St. Jude Children’s Research Hospital who was not involved in the study. Dr. Schultz-Cherry noted that more studies are needed to determine whether the longer shedding duration in obese people is correlated with increased viral load and shedding of infectious viral particles.

She added that this report of longer shedding of virus and a recent study of exhaled breath in college students — which found a link between obesity and the amount of flu virus shedding — suggest that obesity may play an important role in flu transmission. This link has important public health implications, including a threat of more flu transmission that goes along with increasing obesity prevalence. Dr. Schultz-Cherry noted that strategies to prevent flu could be a challenge because of poor vaccine response in overweight and obese populations.

A lung-healing protein could be the reason why men recover from flu faster than women

In the United States, during the 1957 H2N2 pandemic, the number of deaths was higher among females than males. During the first and second wave of the 2009 H1N1 pandemic, a significant portion of patients hospitalized with severe 2009 H1N1 disease was comprised of young adult women. Data from the 2009 H1N1 pandemic, as well as from 2005, which was a bad year for seasonal influenza in Japan, reveal significant differences in morbidity rates between males and females. In 2010, the WHO published a report concluding that the outcome of pandemic influenza, as well as avian (bird flu) H5N1, is generally worse for young adult females.

pregnant woman

Credit: Public Domain

Pregnancy is an obvious female-specific risk factor associated with worse outcomes from seasonal and pandemic influenza infection, and likely contributes to the overall higher mortality in women compared to men. However, it does not appear to explain all of the differences between the sexes. Some researchers have postulated that the slower recovery by women from flu was linked to their greater levels of lung inflammation during flu infections. What else could be the reason?

According to a new study of mice and human cells, increased amounts of a lung-healing protein called amphiregulin (AREG) could be the reason why men recover from influenza more quickly than women. AREG, an Epidermal Growth Factor (EGF)-like molecule, has been shown to play a critical role in wound and tissue healing following infection or injury.

Vermillion, MS et al. Biology of Sex Differences 2018. 9:24

Scientists at Johns Hopkins Bloomberg School of Public Health, whose findings were published in the journal Biology of Sex Differences, infected live mice and human cells derived from male humans with a non-lethal dose of H1N1 — an Influenza A strain that caused over 18,500 laboratory-confirmed deaths worldwide in 2009 and 2010. Male and female mice had the same virus levels and cleared the virus in about the same amount of time.

Nevertheless, female mice had greater loss of body mass and more lung inflammation during the early phase of infection and were slower to return to normal lung function. Male mice genetically engineered to lack AREG had the same flu results as females. In a study of flu infections of mice and human lung epithelial cells in vitro, the investigators found significant increases in the production of AREG only when the cells were from males.

“The novel finding here is that females also have slower tissue-repair during recovery, due to relatively low production of amphiregulin,” study author Dr. Sabra Klein, an associate professor at Hopkins, said in a press release.

Scientists found that AREG, which has been known to promote the growth of epithelial cells in the skin, lung, and other surfaces in the body during wound healing, was the key factor, including during recovery from lung infections. Male mice produced significantly more AREG than females during the recovery phase of their infections.

It is not clear which factors drive the increased rise in AREG production in males during flu infection. Earlier in 2016, Professor Klein and colleagues showed that the sex hormone progesterone stimulates AREG production in female mice. They theorized that males evolved with greater wound-healing ability because they participated in more battles for territories, mates, and resources. The researchers initially thought the production of AREG increased in males during influenza infection because of testosterone. However, they found that the sex hormone, independently of AREG, does help protect male mice, which fared worse in flu infections without it.

Professor Klein’s group is now investigating the mechanisms of testosterone’s protective effect, as well as the factors that control AREG production during flu infection – a better understanding of these mechanisms could lead to new flu treatments that boost AREG production, particularly in women.

Credit: Pixabay.

Dog flu might cause the next influeza pandemic

Just like the H1N1 virus jumped from birds to humans in 2009, so might a new strain of influenza do the same in the future, only this time it could originate from our best friends — dogs.

Credit: Pixabay.

Credit: Pixabay.

After bird and swine flu caused a stir in recent years, a new threat may be on the horizon. Scientists have found that dogs carry an increased diversity of flu strains, as well as evidence that the flu can spread from pigs to dogs, a pattern that’s eerily similar to the build-up for the H1N1 pandemic.

“The majority of pandemics have been associated with pigs as an intermediate host between avian viruses and human hosts,” says one of the researchers, Adolfo García-Sastre, from the Icahn School of Medicine at Mt Sinai in New York.

“In this study, we identified influenza viruses jumping from pigs into dogs.”

Fifteen years ago, researchers documented an influenza virus that had infected a horse before jumping into a canine, signifying the first circulating canine influenza virus. Five years ago, another study reported the first case of influenza passing from a bird to a dog. Now, new research shows that influenza can also circulate from pigs to dogs.

The team of researchers — who are based at the Center for Research on Influenza Pathogenesis Icahn School of Medicine at Mount Sinai in New York City, NY — sequenced the genomes of 16 influenza viruses that were sampled from 800 dogs in Southern China between 2013 and 2015. The canines attended veterinary clinics due to respiratory problems and around 15 percent of them had influenza.

The analysis revealed that viruses that come from swine, and that are avian in origin, are now jumping into dogs.

“We now have H1N1, H3N2, and H3N8 in dogs. They are starting to interact with each other. This is very reminiscent of what happened in swine 10 years before the H1N1 pandemic,” the authors reported.

In 2009, avian flu jumped to pigs, where it mixed with existing strains, ultimately leading to a hybrid virus that could infect humans. It was a totally new strain to which humans had not had the chance to develop any immunity against.

The present findings, however, don’t imply that flu strains developing in dogs are going to be harmful to humans. It’s just that they might. As the viruses mix and become more diverse, the chances increase that they could become capable of infecting humans. That being said, there is no reason to panic yet — especially considering that the dogs included in the study were sampled from a single region of China. If in the future scientists find any reason for concern, the virus can be kept at bay through vaccination programs.

The findings have been published in the journal mBio.

Scientists identify new Flu H1N2 from a mix of two other influenza viruses

Mutation is an important source of RNA virus diversity that happens because the nature of RNA synthesis is prone to error. This is one of the reasons why the flu vaccine composition is changed each year. For influenza viruses, with segmented genomes, another mechanism for generating diversity is through reassortment. If a cell is infected with two different influenza viruses, the RNAs of both viruses are copied in the nucleus. When new virus particles are assembled, each of the RNA segments may originate from either infecting virus. The resulting “new” flu viruses inherit RNAs from both parents and are called reassortants.

From Eric J. Ma (Department of Biological Engineering, MIT)


Tests in the Netherlands identified a reassortant H1N2 seasonal flu infection in a toddler who was seen at a clinic that was part of the sentinel surveillance network. The flu virus is described as reassortant because it is a mix of A(H3N2) and A(H1N1) – the flu virus has eight gene segments and this particular virus consists of 6 gene segments from the A(H3N2) virus (PB1, PB2, PA, NP, NA, M) and 2 gene segments from the A(H1N1)pdm09 virus (HA, NS).

Reassortant Flu H1N2 (Dr Melvin Sanicas)


The 19-month-old boy’s symptoms began in early March, and he was taken to a clinic three days later. He had not traveled, been vaccinated, taken antivirals and had no underlying health conditions. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) and nanopore sequencing confirmed the H1N2 reassortant in mid-March. After the boy’s initial clinic visit, he was seen again for an ear infection and he recovered fully after antibiotic treatment.

According to the investigators, increased virulence (severity of the resulting disease symptoms) is not expected and there were no mutations to suggest resistance to antivirals had been identified. Reassortant seasonal viruses have been reported previously. The spread of these viruses was limited, but in one case, circulation continued for three seasons with a reassortant of a former seasonal A(H1N1) and A(H3N2) influenza virus. A reassortant of A(H1N1)pdm09 and A(H3N2) has only been found in India. In the Netherlands, the 2017-2018 influenza season is dominated by influenza B/Yamagata lineage viruses, but the Dutch National Influenza Center characterized around 600 influenza type A viruses, only one of which (the case reported here) was of the H1N2 subtype. There is thus no evidence of an extensive spread of the A(H1N2) virus, but laboratories should remain on alert. The rise of a reassortant that contains the 2009 H1N1 virus would be a serious concern, because the 2009 H1N1 virus is well-adapted to humans and presents an ideal background for the spread of novel strains.

Flu vs cold

How to spot the difference between a cold and the flu

Flu vs cold

Credit: Pixabay / Sambeet.

It’s common to dismiss a few sniffles and a cough as ‘nothing but a cold’ when, in fact, it might very well be a far more dreadful animal — influenza. It’s quite easy to mistake the two, too. Both are viral infections and symptoms often overlap. Sometimes, unless your doctor runs a test with a cotton swab from the back of your nose or throat, it can be very difficult to tell the two apart. Make no mistake though — the two types of viral infections can also be worlds apart, so much so that it could mean the difference between life and death. While the common cold is generally harmless, tens of thousands of people worldwide die each year from the flu.

Flu vs common cold

Flu symptoms include:

  • Fever or feeling feverish/chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Fatigue (tiredness)
  • Some people may have vomiting and diarrhea, though this is more common in children than adults.

Cold symptoms overlap greatly, but they’re typically milder than those of the flu. Another important difference in this regard is that people with colds are more likely to have a runny or stuffy nose.

Precisely because the symptoms of the two types of infection overlap so much, it can be very difficult if not impossible to diagnose one or the other based on symptoms alone. Instead, doctors rely on special tests performed within the first couple of days of illness to make the diagnosis. It’s a good idea to get tested within the first 48 hours of showing symptoms to minimize the risk of developing flu-related health complications.

The flu can lead to sinus and ear infections (moderate) or more serious complications such as pneumonia, inflammation of the heart (myocarditis), brain (encephalitis) or muscle (myositis, rhabdomyolysis) tissues, and multi-organ failure (for example, respiratory and kidney failure). Colds generally do not result in serious health problems.

Both the flu (influenza) and the common cold are viral infections of the upper respiratory tract but each is caused by different groups of viruses.  However, influenza can also infect the lungs and the joints, and can cause pneumonia, respiratory failure, and even death.

Credit: WebMD.

Credit: WebMD.

Colds come on gradually over a few days and are often milder than the flu. They usually get better in 7 to 10 days, although symptoms can last for up to 2 weeks.

Flu symptoms come on quickly — often within 1 to 3 days — and can be severe. Basically, if you wake up one morning suddenly feeling like you’ve been hit by a truck, it’s likely the flu. Symptoms usually last 1 to 2 weeks.

Influenza is responsible for body and head aches, whereas cold aches are much milder.

With a cold, you may or not feel tired. With the flu, however, tiredness and weakness are common.

Some people get a slight fever when struck by a cold, but most don’t. In contrast, any fever above 38 degrees Celsius (101 to 104 degrees Fahrenheit) is a sign of the flu, with children’s fevers tending to be higher.

Bottom line: fever, fatigue and muscle aches may be a sign of both types of viral infections, but if they are particularly bad it is likely to be the flu. Nasal symptoms are more likely to point to a cold. Flu comes on faster while, in contrast, a cold develops more gradually. Flu symptoms usually go away after a week; if they persist for up to two weeks, it’s probably a cold. There is a vaccine for the flu but none for the cold.

What is the common cold?

Common cold vs flu

Credit: Pixabay.

The common cold is an upper respiratory viral infection caused by an adenovirus, rhinovirus or coronavirus. More than 100 different viruses can cause the common cold, meaning there’s a lot of variability. For this reason, you’ll often hear that there’s no cure for the common cold nor is there any vaccination (a common cold vaccine might actually be in sight though). It’s true, however, that the rhinovirus is most often the one that makes people sneeze and sniffle.

Cold-causing viruses thrive in low humidity which is why they’re so common during winter months. These are airborne viruses which typically spread when someone sick sneezes or coughs. You can also get infected if you come in contact with a surface that a sick person also contacted and then touch your nose, mouth, or eyes.

Infected people are more contagious in the first two to four days after being exposed to the virus.

Common cold treatments

Over-the-counter medications, such as antihistamines, decongestants, acetaminophen, and NSAIDs, can relieve congestion, aches, and other cold symptoms. Drinking plenty of fluids to avoid dehydration is key.

However, there’s mixed evidence that remedies like zinc, vitamin C or echinacea prevent or relieve cold symptoms. A 2015 study found taking zinc lozenges could shorten the length of colds if taken within 24 hours of showing symptoms. Vitamin C doesn’t look like it prevents colds, but when taken regularly may lessen cold symptoms, according to a 2013 review. 

[ALSO READ] Why am I always cold? 

It’s always a good idea to read the active ingredients and warnings on all product labels. Many cough and cold medicines have the same ingredients, so you could accidentally overdose unless you’re careful.

Don’t ever take antibiotics for colds since this is a viral infection and not a bacterial infection. Viral infections typically go away seven to ten days after the first symptoms show. If symptoms persist after that, you might have bacteria like Strep or Haemophilus influenzae. These bacteria cause illnesses that are longer lasting.

What is the flu?

cold vs flu.

Credit: Pixabay.

The flu is also an upper respiratory viral infection. It’s caused by the influenza virus which is less variable and hence can actually be preventable. For instance, there are various flu vaccines.

Seasonal flu is caused by influenza A, B, and C, with A and B being the most common. New vaccines have to be developed every flu season though because active strains vary yearly. There are scientists, however, who are working on a universal flu vaccine. 

The flu spreads from to person to person just like the cold: by coming into contact with droplets spread by an infected person. Infected people are contagious starting 1 day before getting sick and up to 5 to 7 days after showing symptoms.

Unlike the common cold, the flu can easily develop into a more serious condition, particularly in the case of young children, older adults, pregnant women, and people with weakened immune systems.

Flu treatments

To shorten the duration of the flu infection and to prevent complications, your doctor may prescribe antiviral drugs such as oseltamivir or zanamivir. However, this kind of treatment only works within the first 48 hours of getting sick. If you’re too late, you can treat symptoms with over-the-counter pills like ibuprofen and acetaminophen. At the end of the day, though, there’s not much you can do other than resting and drinking plenty of fluids. If symptoms get worse, you ought to urgently see a doctor for any signs of complications such as pneumonia (severe sore throat, trouble breathing, chest pain, high and persistent fever).

The best way to prevent the flu is getting the flu shot, the best time to do this being in October (the start of flu season). Unfortunately, only 30 percent of 4,000 U.S. adults surveyed said they’d been inoculated this season.

To avoid contracting the viral infection, wash your hands often with soap and warm water. Most importantly, avoid touching your nose, eyes, and mouth. Stay away from people who have the flu or flu-like symptoms.

Regardless of whether you have a cold or the flu, the illness will usually go away on its own, but you should visit your doctor if your symptoms change or get worse.

Illustration of influenza virus. Credit: Pixabay.

Unvaccinated children account for majority of pediatric deaths due to the flu

Dying of the flu isn’t common at all, especially for children. However, a new study suggests that most pediatric deaths caused by the flu are of children who weren’t vaccinated. The findings underscore yet again the importance of vaccine efficacy and immunization.

Illustration of influenza virus. Credit: Pixabay.

Illustration of influenza virus. Credit: Pixabay.

74% of the children who had died of the flu were unvaccinated

The researchers from the Centers for Disease Control and Prevention analyzed the health records of 291 of the 358 American children between 6 months and age 17 who had died of the flu between 2010 and 2014. These records suggest that in only 26 percent of these fatalities were the children vaccinated against influenza.

A flu vaccine makes children far less susceptible to serious flu but sometimes an underlying illness chips away at a person’s immune system making the vaccine less effective than in healthy people. In all, 153 of the children who died had high-risk medical conditions, like asthma, blood and endocrine disorders, or neurological problems. But even among them, only 31 percent had been vaccinated.

“There are always vaccine failures,” said Lyn Finelli, DrPH, chief of the CDC’s surveillance and outbreak response team in 2011. “Say a vaccine is 90% effective. You are going to see those 10% of vaccine failures in statistics on deaths and hospitalizations. It makes you think the vaccine works less well than it does. You never see the vast majority of people for whom the vaccine works.”

The effectiveness of the vaccine among children with high-risk health conditions was at 51 percent, which the authors class as a ‘significant’ benefit. Children who suffer from common risk factors are the most vulnerable and should be vaccinated. Overall, vaccine effectiveness against death was found to be 65 percent, as reported in the journal Pediatrics

The study highlights yet again the importance of annual influenza vaccination, despite what many parents may hear about vaccines. The so-called ‘anti-vaxxing’ movement has targeted also flu vaccines which may contain thimerosal, a mercury-based preservative which is falsely attributed to rising autism incidence in the United States.

“Results of this study suggest that vaccination reduced the risk of influenza-associated death among children and adolescents and add to the evidence of benefits of influenza vaccination for children. Annual vaccination is an important strategy to prevent influenza and influenza-associated complications and deaths. These results support current recommendations for annual influenza vaccination for all children ≥6 months of age,” the study concludes.




Credit: Pixabay.

Vitamin D can protect against flu and cold, meta-analysis study confirms

Credit: Pixabay.

Credit: Pixabay.

A meta-analysis of 25 randomized controlled trials involving over 11,000 participants confirmed that vitamin D supplementation can stave off acute respiratory infections.

“Most people understand that vitamin D is critical for bone and muscle health,” said Carlos Camargo, MD, DrPH, of the Department of Emergency Medicine at Massachusetts General Hospital (MGH) and the study’s senior author. “Our analysis has also found that it helps the body fight acute respiratory infection, which is responsible for millions of deaths globally each year.”

This was a highly challenging work since many of these studies had different designs or participant qualifications. Some concluded that low Vitamin D levels were linked to a greater risk of developing an acute respiratory infection. Other clinical trials, on the other hand, which investigated the protective abilities of Vitamin D supplements reached opposing conclusions. Some found Vitamin D supplementation staves off infections while other found no conclusive evidence that this is the case.

The team led by Adrian Martineau from the Queen Mary University of London aggregated all of the data from these 25 trials by conducting an individual participant data meta-analysis. Typically, a meta-analysis averages data from all participants in each study. This was not the case. The researchers, instead, separated out the data from each individual participant to obtain a higher resolution analysis of the data from all these mammoth studies.

The conclusion is that daily or weekly supplementation had the greatest benefit for those individuals that had a Vitamin D deficiency, to begin with. Those with the lowest levels of Vitamin D (blood levels below 10 mg/dl) cut their risk of respiratory disease by half. All participants experience some beneficial effect from regular Vitamin D supplementation. Occasional high doses of vitamin D had no effect.

“Acute respiratory infections are responsible for millions of emergency department visits in the United States,” says Camargo, who is a professor of Emergency Medicine at Harvard Medical School. “These results could have a major impact on our health system and also support efforts to fortify foods with vitamin D, especially in populations with high levels of vitamin D deficiency.” The study was funded by a grant from the National Institute of Health Research (U.K.).

According to recommendations from the Institute of Medicine, most adults need about 600 IU (international units) of vitamin D per day while the elderly (over 70 years) are advised to intake 800 IUs per day.

We get our Vitamin from what we eat but also sourced from our own bodies as these produce Vitamin D when in contact with sunlight. A good Vitamin D-rich diet might include milk and other dairy products, orange juice, cereal, as well as sardines and other fish products which contain a high level of Vitamin D.

Since this is a meta-study, you should take the conclusion with caution. After all, some of the studies found that supplements don’t work. The standard multivitamin has about 400 IUs but if you’re already intaking 600 IUs, it’s not clear you need to take a supplement despite the current meta-analysis suggests ‘all participants can experience beneficial effects from supplementation.’

It’s best you visit your doctor who can check your Vitamin D levels. She will tell you the right course of action. Chances are you’re not deficient.

The findings appeared in The New England Journal of Medicine