Virologists are trying to keep up with the faster evolution of the coronavirus.

The rapid evolution of the coronavirus into an alphabet soup of subvariants presents a vexing challenge for health officials: they must make far-reaching policy decisions based on little biological certainty about which viral variants will dominate this fall or winter.

The Food and Drug Administration reported at the end of June. that he will update the coronavirus vaccines for the booster campaign in autumn they target highly contagious Omicron subvariants. But the ground is slipping away from under your feet.

In just eight weeks sub-variant known as BA.5 gone from a spike in US case counts to dominant version of the virus in the country, which now accounts for more than three-quarters of new cases. It is arguably the most contagious sub-variant, increasing positive tests, admissions, and intensive care admissions across the country.

There is no evidence that BA.5 causes more severe illness, but recent figures certainly shatter the myth that the virus will get milder as it progresses.

“None of us have a crystal ball and we are trying to use every last ounce of what we can from the predictive modeling and data that we have to try to get ahead of the virus, which has been very tricky,” the doctor said. Peter Marks, chief vaccine regulator at the FDA, after an advisory committee recommended that the agency prioritize vaccines specific to Omicron sub-options. “For something as small as nanometers, that’s pretty damn clever. We’re trying to do our best here.”

Omicron and its offshoots have been dominating for about six months now, and any incarnation of the virus that comes next is more likely to be related to the Omicron family than to earlier versions. Jerry Weir saidsenior FDA regulator.

This assumption is the best estimate currently available, according to third-party experts outside the FDA panel.

“Viruses like SARS-CoV-2 are constantly evolving and it is almost certain that new mutants will emerge in any given six-month period,” said Jesse Bloom of the Fred Hutchinson Cancer Center in Seattle. “But as long as these mutants are descendants or close relatives of BA.2 or BA.4/BA.5, the BA.4/BA.5-based booster vaccine, as recommended by the FDA, should be much better. match them than the current vaccine, even if it’s not a perfect match.”

Centers for Disease Control and Prevention on Tuesday cleared the fourth vaccinefrom Novavax, for use in the United States, but trials were conducted prior to the introduction of Omicron and its effectiveness against the variant may have been limited.

The Omicron family tree has been growing faster since Omicron BA.1 was first discovered at the end of November 2021. New federal estimates showed on Tuesday that BA.5 accounted for about 78 percent of new cases in the United States as of last week.

Emma Hodcroft, a molecular epidemiologist and researcher at the University of Bern in Switzerland, said the model for Omicron’s evolution differs from earlier versions. “The Delta kids weren’t dominant, but the Omicron kids supplant their siblings, if you will,” she said. “This hints that Omicron is at its peak and that there will be small changes.”

While there may be more Omicron babies on the way, she and other scientists stressed that this doesn’t rule out another possibility.

“Too many times we have made predictions about how we think SARS-CoV-2 will develop and then turned out to be flat out wrong,” said Nathan Grubo, an epidemiologist at the Yale School of Public Health. Last fall, he correctly predicted that an immunity evading subvariant would emerge, but his expectation that it would come from the Delta variant was wrong.

“Obviously there are new options coming up inside Omicron right now — BA.2, BA.4 and BA.5 — and that could continue,” he said. “But we must not lose our imagination and think that this will continue to be so.”

Last year, Sarah Kobey, an evolutionary biologist at the University of Chicago, was pretty sure the next variant would come from the delta. “However, I think the next option is likely to come from Omicron,” she said last week, adding that it could have a wider immune evasion or increased transmissibility. “Probably, the next option has already appeared, but for some time it will elude observation,” she said.

Omicron’s sinister cousin, BA.2.75, has already been spotted in parts of the world.

This makes adjusting the booster formula more important, says Christian Andersen, a virologist at the Scripps Research Institute in La Jolla, California. The benefits of such a move, he says, are far more to do with expanding immunity than increasing protection against a very specific variant. According to him, early variants did not descend from previous variants, but rather from earlier lines, unlike Omicron, which makes it difficult to predict.

Forecasting, however, is the asset of every trading expert.

“We’ve been trying for decades to better guess the next variant of the flu,” the doctor said. Hodcroft said. “And it turns out to be very difficult.”

Many variables mean that she and other experts cannot make a statement with complete certainty. She said, “It’s very difficult to put it all in a machine and grind it.”