Omikron sub-variants ‘BQ.1’ and ‘BQ.1.1’ will soon conquer the United States | National Geographic

As the United States braces for another wave of COVID-19 infections, scientists are concerned about the sudden and rapid spread of the new Omikron sub-variants. Out data of the U.S. Centers for Disease Control and Prevention (CDC) published last week, subvariants BQ.1 and BQ.1.1 now account for more than ten percent of all cases, while subvariant BF.5 is found in five others the percentage of American patients.

According to John Swatzberg, an infectious disease and vaccinology expert at the University of California, Berkeley School of Public Health, the situation could “reverse in a matter of weeks” if these sub-variants continue to spread at this rate. “One or all three strains could replace the existing Omikron BA.5 sub-variant as the more prevalent SARS-CoV-2 strain.” (Global experts are also concerned other sub-variants of Omikron, such as XBB.)

What exactly are these sub-variants and how do they differ from previous strains? Let’s summarize the most important facts.

What are “B1.1”, “Q.1”, “BQ” and “BF.7”?

The three sub-variants of Omikron that are currently spreading rapidly in the United States are all descendants of BA.5, the sub-variant that is still responsible for about two-thirds of all COVID-19 infections in the United States. As before from National Geographic was reportedall of Omikron’s descendants are worrying because they share a number of characteristics: they spread more easily than previous variants and can bypass accumulated antibodies against COVID-19.

According to Stuart Rayan infectious disease expert at Johns Hopkins University in Baltimore, Maryland, BQ.1, BQ.1.1 and BF.7 are of particular concern because these subvariants have developed mutations in protein receptors on the spikes of the coronavirus, a component that is critical to its ability to evade the human immune system.

Ray sees these sub-variants as examples of a phenomenon called “convergent evolution,” a process in which different organisms go through the same evolution independently of each other. “The changes in that area of ​​the spikes occur across numerous lineages, suggesting that these mutations confer important evolutionary benefits,” he says. “Even if the tribes develop independently of each other, they find the same solutions for the same challenges.”

Are the new sub-variants more dangerous?

Although these sub-variants are believed to be better at evading antibodies, there is little evidence that they cause a more severe disease course than previous strains.

Scientists worry that the new sub-variants also appear to be good at bypassing drugs given to people with weak immune systems or vulnerable to a severe disease course. White House Chief Medical Advisor Anthony Fauci said: in front of CBS News that BQ.1.1. apparently capable of “evading important monoclonal antibodies”. These antibodies are used in drugs such as tixagevimab and are designed to bind to the same region of the protein receptors at the virus tips where previous mutations have led to new subvariants. More research is needed to confirm this problem.

Ray points out that it is difficult to compare the pathogenicity of the new sub-variants with that of the previous strains, given the level of immunity that has built up in the population. Therefore, it is entirely possible that these sub-variants would have caused far more damage had they emerged before the introduction of current COVID-19 vaccines.

“If people don’t maintain their immunity with the help of vaccines, we could see an increase in the number of severe cases,” he says. Even with mild illnesses, there is every reason to be concerned about a recurrence of cases, as these types of repeat infections are associated with cardiovascular disease, brain disorders, and post-COVID-19 complications. “Vaccination is the way to maintain immunity and our best solution now is bivalent vaccines.”

Protection against sub-variants

Sufficient data are not yet available to answer the question of whether bivalent vaccines – new versions of the original vaccines that specifically protect against Omikron BA.4 and BA.5 sub-variants – also protect against the new sub-variants. So why are most experts quite optimistic? Ashish Jha, White House COVID-19 Coordinator, last week wore a Press conference found that the three new subvariants all descend from the Omikron BA.5 subvariant.

“This means that our upgraded bivalent vaccines should provide a much higher degree of protection than the original prototype vaccine,” he says. “Obviously, we will investigate exactly how much protection is involved, but I am confident that our modified vaccines will continue to work well, especially against a severe disease course.”

Philip Chan, assistant professor of medicine at Brown University in Providence, Rhode Island, believes the new bivalent boosters are particularly popular. She points out that most experts believe that the original vaccines still offer protection against serious illness and hospitalization, as was the case with the variants that emerged during the pandemic.

And now?

Most experts believe that the new sub-variants make it clear that vaccines and the use of masks are still very important and could become even more important if monoclonal antibodies are found not to work well against the latest versions of the coronavirus.

“What these new mutations are telling us is that the virus is not done with us yet,” Swartzberg says. While no one can predict how the virus will develop further, he thinks we can assume that the number of cases of the disease in the United States will increase dramatically over the next six to eight weeks.

“I’m sure the lull we’re going through right now won’t last until after Thanksgiving.” [24 november],’ he says. “We should do everything we can to protect ourselves, our families and our community from new infections.”

This article was originally published in English on nationalgeographic.com