The US Food and Drug Administrationan independent panel of advisers on Thursday recommended that updated Covid images for autumn and winter destination one of XBB variantswhich are now nationally dominant strains of the virus.

The committee unanimously voted that the new shots should be monovalent – ​​meaning they are designed to protect against a single variant Covid — and focus on a member of the XBB family.

These tribes The covids are descendants omicron variantwhich caused cases of k jump to record levels early last year. They are some of the strains that have so far evaded immunity the most.

The advisors also generally agreed that the new footage should specifically target the so-called XBB.1.5. The panel only discussed this particular strain selection and did not vote on the matter.

XBB.1.5 accounted for nearly 40% of all US Covid cases in early June, according to data from the Centers for Disease Control and Prevention. This proportion is slowly declining and cases of the related variants XBB.1.16 and XBB.2.3 are on the rise.

Advisors noted that XBB.1.5 appears to be the most ideal for fall from vaccine manufacturers Pfizer, modern and Novavax they have already begun to develop strikes aimed at the tribe.

“1.5 looks good. It seems most feasible to get across the finish line early without delay and availability,” said Dr. Melinda Wharton, senior official at the National Center for Immunization and Respiratory Diseases. “The vaccine that we can use is the vaccine that we can get. And so it seems like that would be a good choice.”

The FDA usually follows the advice of its advisory committees, but it is not mandatory. It’s unclear when the agency will make a final decision on the tribe’s selection.

There is also uncertainty about which age groups the FDA and CDC will recommend receiving updated footage this fall.

But the panel’s recommendation is already a win for Pfizer, Moderna and Novavax — all of which were conducting early trials on their respective XBB.1.5 shots prior to the encounter.

“Novavax expects to be ready for commercial delivery of the protein monovalent XBB COVID vaccine this fall in accordance with today’s [advisory committee] recommendations,” said John Jacobs, the company’s president and CEO.

It is expected from the US vaccine distribution shift to the private sector this fall. This means that vaccine manufacturers will start selling theirs the new covid products directly to healthcare providers and compete for commercial market share.

The panel’s recommendation coincides with a broader shift in how the pandemic affects the country and the world at large.

Covid cases and deaths have he dropped to new lows, governments rolled back strict health requirements such as masking and social distancing, and many people believe it the pandemic is over in total.

But Dr. Peter Marks, director of the FDA’s vaccine division, said the agency is concerned the US will have another wave of Covid “as the virus continues to evolve, population immunity continues to weaken and we move indoors for the winter.” .”

Updated Covid vaccines, which are regularly updated to target the highly circulating variant, will restore protective immunity against the virus, said Dr. David Kaslow, a senior official in the FDA’s Division of Vaccines.

It is a similar approach to how strains are selected annual flu vaccination. Scientists are assessing the strains of the virus in circulation and estimating which will be most prevalent during the coming fall and winter.

But it’s unclear how many Americans will roll up their sleeves to get the updated pictures later this year.

Just about 17% of the US population — about 56 million people — have received the Pfizer and Moderna boosters since their approval in September, according to the CDC.

More than 40% of adults age 65 and older were boosted by these doses, while the rate among younger adults and children is between 18% and 20%.

These boosters were bivalent, meaning they targeted the original Covid strain and the omicron subvariants BA.4 and BA.5.

During the meeting, Pfizer, Moderna and Novavax presented preliminary data on updated versions of their missiles designed to target XBB variants.

Moderna was evaluating shots targeting XBB.1.5 and XBB.1.16 — another portable descendant of omicrons, according to Rituparna Das, the company’s vice president of Covid vaccines.

Data from preclinical studies in mice suggest that a monovalent vaccine targeting XBB.1.5 generates a more robust immune response against currently circulating XBB variants than the licensed bivalent vaccine targeting BA.4 and BA.5, according to Das.

She added that data from clinical trials in more than 100 people similarly demonstrate that the monovalent XBB.1.5 vaccine produces protective antibodies against all XBB variants. All study participants had previously received four doses of the Covid vaccine.

Das said the complex protection against XBB strains is likely due to fewer unique mutations between the variants, meaning their makeup is similar.

According to Darin Edwards, head of Moderna’s Covid vaccine program, there are only three unique mutations between the XBB.1.5 and XBB.1.16 variants. In comparison, there are 28 mutations between omicron BA.4 and BA.5.

That means the immune response that the updated shot elicits against the XBB variants is likely to be similar regardless of which particular variant it targets, Edwards said.

Pfizer also presented data from early studies suggesting that a monovalent vaccine targeting the XBB variant offers improved immune responses against the XBB family.

The company provided specific timelines for delivery of the updated vaccine depending on the strain the FDA selects.

Pfizer will be able to deliver a monovalent shot targeting XBB.1.5 by July and a shot targeting XBB.1.16 by August, according to Ken Swanson, the company’s chief scientific officer.

Pfizer won’t be able to distribute the new dose until October if the FDA chooses a completely different strain, Swanson said.

Novavax did not provide a specific timeline for the delivery of the XBB.1.5 shot, but noted that the XBB.1.16 shot will take eight weeks longer.

Novavax disclosed data from preclinical studies indicating that monovalent vaccines targeting XBB.1.5 and XBB.1.16 induce higher immune responses to XBB subvariants than bivalent vaccines.

The data also show that injecting XBB.1.5 produces antibodies that block XBB.2.3 from binding to and infecting human cells, says Dr. Filip Dubovský, chief physician of Novavax.

Dubovsky said the test results support the use of the XBB.1.5 monovalent missile in the fall.

Novavax’s strike uses protein-based technologya decades-old method of combating viruses used in routine hepatitis B and shingles vaccinations.

The vaccine works differently than the messenger RNA vaccines of Pfizer and Moderna, but it achieves the same result: it teaches your body how to fight Covid.