Tag Archives: variant

A new Omicron subvariant, 30% more contagious, is starting to sweep the world

I know — we’re all tired of the pandemic and we’re all hoping it’d be over by now. But unfortunately, the virus doesn’t really care about media fatigue or how tired we all are of this pandemic.

While substantial progress has been made on the vaccination front, new variants continue to emerge, and researchers warn that the pandemic is still not done yet. Now, a new Omicron variant (BA.2) is surging in several parts of the world, including the US, UK, and Hong Kong.

Graph made by William Ku, with data from the CDC.

Researchers warned us from the beginning that until we reach herd immunity at a global level, new variants will continue to emerge and we’d still be stuck in a pandemic — and this is exactly what we’re seeing now. After the more contagious Delta variant came in and swooped over the Alpha and Beta variants, Omicron made it all look like a joke.

The contagiousness math adds up very quickly.

Alpha was 50% more contagious than the original Wuhan strain. Delta is 40-60% more contagious than Alpha. Omicron is 105% more contagious than Delta. Now, the BA.2 Omicron variant appears to be 30% more contagious than the original Omicron, and we’re seeing the number of cases spike accordingly.

The emergence of the new subvariant coincides with a wave of lifting restrictions. Countries (especially those with a relatively high level of vaccination) were quick to relax restrictions and ease the political, social, and economic pressure they were causing — but this has come at a cost.

In the UK, the BA.2 variant has become dominant, and while at some point it seemed that the Omicron wave would simply burn out in the country, we’re seeing a new surge in cases and hospitalizations are starting to follow.

What we know about BA.2 Omicron so far

While it clearly appears to be more transmissible (and will likely become dominant across the world), we still don’t know how severe this subvariant is. Lab experiments from Japan suggest that it may have Delta-like characteristics and may cause more severe illness.

“More importantly, the viral RNA load in the lung periphery and histopathological disorders of BA.2 were more severe than those of BA.1 and even B.1.1. Together with a higher effective reproduction number and pronounced immune resistance of BA.2, it is evident that the spread of BA.2 can be a serious issue for global health in the near future,” a study not yet peer-reviewed concludes.

However, a separate study from South Africa found that a similar proportion of individuals with BA.1 and BA.2 infections required hospitalization, and data from Denmark suggests similar hospitalization rates for BA.1 and BA.2.

As is always the case with new variants and subvariants, it’s hard to tell exactly how things stand in the beginning. It’s also curious that while it seems to be taking over in several parts of Asia and Europe, BA.2 transmission in the US seems relatively low.

Importantly, while Omicron BA.2 shows some ability to evade vaccine immunity, it seems that boosters still provide excellent immunity. Overall, BA.2 shows the already well-known Omicron ability to evade some of the protection offered by two shots — but three shots offer over 90% protection against hospitalization.

Image credits: William Ku, with data from the CDC.

Long-term, it seems that booster-provided protection wanes in time, and the rate of booster shot delivery has also slowed down, presumably as people’s interest in the pandemic also wanes. But variants don’t care how much attention you’re paying.

Did we rip the bandaid too soon?

Another reason why BA.2 is spreading so quickly is that many countries have relaxed restrictions — or removed them altogether. Some researchers believe this was done too quickly.

In addition to extra transmissibility, the BA.2 subvariant also appears to be capable of escaping some of the treatments we have for COVID-19. While the original Omicron was capable of evading two of the four monoclonal antibody drugs used in infections in high-risk individuals, a study from New York University suggests that BA.2 can bypass a third drug, sotrovimab.

Researchers also caution that even mild cases can cause lasting brain damage (and potentially other problems as well). A study from Oxford found that the virus produces changes in the brain and may shrink grey matter.

Ultimately, the vast majority of people with booster shots should be able to evade the worst of the virus effects — but they can still be in for an unpleasant ride.

Immune cells from the common cold offer protection against COVID-19, researchers find

If one in 10 cold infections are from coronaviruses, then antibodies produced from these illnesses could surely give a bit more protection against COVID-19, right? A new study has just provided the answer to this question by showing that immunity induced by colds can indeed help fight off the far more dangerous novel coronavirus.

Image credits: Engin Akyurt.

A study from Imperial College London that studied people exposed to SARS-CoV-2 or COVID-19 found that only half of the participants were infected, while the others tested negative. Before this, researchers took blood samples from all volunteers within days of exposure to determine the levels of an immune cell known as a T cell – cells programmed by previous infections to attack specific invaders.

Results show that participants who didn’t test positive had significantly higher levels of these cells; in other words, those who evaded infection had higher levels of T cells that attack the Covid virus internally to provide immunity — T cells that may have come from previous coronavirus infections (not SARS-CoV-2). These findings, published in the journal Nature Communications, may pave the way for a new type of vaccine to prevent infection from emerging variants, including Omicron.

Dr. Rhia Kundu, the first author of the paper from Imperial’s National Heart & Lung Institute, says: “Being exposed to the SARS-CoV-2 virus doesn’t always result in infection, and we’ve been keen to understand why. We found that high levels of pre-existing T cells, created by the body when infected with other human coronaviruses like the common cold, can protect against COVID-19 infection.” Despite this promising data, she warns: “While this is an important discovery, it is only one form of protection, and I would stress that no one should rely on this alone. Instead, the best way to protect yourself against COVID-19 is to be fully vaccinated, including getting your booster dose.”

The common cold’s role in protecting you against Covid

The study followed 52 unvaccinated people living with someone who had a laboratory-confirmed case of COVID-19. Participants were tested seven days after being exposed to see if they had caught the disease from their housemates and to analyze their levels of pre-existing T cells. Tests indicated that the 26 people who tested negative for COVID-19 had significantly higher common cold T cells levels than the remainder of the people who tested positive. Remarkably, these cells targeted internal proteins within the SARS-CoV-2 virus, rather than the spike protein on its surface, providing ‘cross-reactive’ immunity between a cold and COVID-19.

Professor Ajit Lalvani, senior author of the study and Director of the NIHR Respiratory Infections Health Protection Research Unit at Imperial, explained:

“Our study provides the clearest evidence to date that T cells induced by common cold coronaviruses play a protective role against SARS-CoV-2 infection. These T cells provide protection by attacking proteins within the virus, rather than the spike protein on its surface.”

However, experts not involved in the study caution against presuming anyone who has previously had a cold caused by a coronavirus will not catch the novel coronavirus. They add that although the study provides valuable data regarding how the immune system fights this virus, it’s unlikely this type of illness has never infected any of the 150,000 people who’ve died of SARS-CoV-2 in the UK to date.

Other studies uncovering a similar link have also warned cross-reactive protection gained from colds only lasts a short period.

The road to longer-lasting vaccines

Current SARS-CoV-2 vaccines work by recognizing the spike protein on the virus’s outer shell: this, in turn, causes an immune reaction that stops it from attaching to cells and infecting them. However, this response wanes over time as the virus continues to mutate. Luckily, the jabs also trigger T cell immunity which lasts much longer, preventing the infection from worsening or hospitalization and death. But this immunity is also based on blocking the spike protein – therefore, it would be advantageous to have a vaccine that could attack other parts of the COVID virus.

Professor Lalvani surmises, “The spike protein is under intense immune pressure from vaccine-induced antibodies which drives the evolution of vaccine escape mutants. In contrast, the internal proteins targeted by the protective T cells we identified mutate much less. Consequently, they are highly conserved between the SARS-CoV-2 variants, including Omicron.” He ends, “New vaccines that include these conserved, internal proteins would therefore induce broadly protective T cell responses that should protect against current and future SARS-CoV-2 variants.”

New COVID variant identified in France — but experts say we shouldn’t fear it

Scientists have identified a previously unknown mutant strain in a fully vaccinated person who tested positive after returning from a short three-day trip to Cameroon.

Academics based at the IHU Mediterranee Infection in Marseille, France, discovered the new variant on December 10. So far, the variant doesn’t appear to be spreading rapidly and the World Health Organization has not yet labeled it a variant of concern. Nevertheless, researchers are still describing and keeping an eye on it.

The discovery of the B.1.640.2 mutation, dubbed IHU, was announced in the preprint server medRxiv, in a paper still awaiting peer review. Results show that IHU’s spike protein, the part of the virus responsible for invading host cells, carries the E484K mutation, which increases vaccine resistance. The genomic sequencing also revealed the N501Y mutation — first seen in the Alpha variant — that experts believe can make COVID-19 more transmissible.  

In the paper, the clinicians highlight that it’s important to keep our guard and expect more surprises from the virus: “These observations show once again the unpredictability of the emergence of new SARS-CoV-2 variants and their introduction from abroad,” they write. For comparison Omicron (B.1.1.529) carries around 50 mutations and appears to be better at infecting people who already have a level of immunity. Thankfully, a growing body of research proves it is also less likely to trigger severe symptoms.

Like many countries in Europe, France is experiencing a surge in the number of cases due to the Omicron variant.

Experts insist that IHU, which predates Omicron but has yet to cause widespread harm, should not cause concern – predicting that it may fade into the background. In an interview with the Daily Mail, Dr. Thomas Peacock, a virologist at Imperial College London, said the mutation had “a decent chance to cause trouble but never really materialized. So it is definitely not one worth worrying about too much at the moment.”

The strain was first uploaded to a variant tracking database on November 4, more than two weeks before Omicron was sequenced. For comparison, French authorities are now reporting over 300,000 new cases a day thought to be mostly Omicron, with data suggesting that the researchers have identified only 12 cases of IHU over the same period. 

On the whole, France has good surveillance for COVID-19 variants, meaning health professionals quickly pinpoint any new mutant strains. In contrast to Britain, which only checks three in ten cases for variants. The paper’s authors state that the emergence of the new variant emphasizes the importance of regular “genomic surveillance” on a countrywide scale.