Covid vaccines this fall should target XBB variant, FDA advisors say

The US Food and Drug Administration’s independent panel of advisors on Thursday recommended That the updated Covid shots for the fall and winter seasons target one of the XBB variants, which is now The dominant strains of the virus nationwide.

the A committee He voted unanimously that the new vaccines should be monovalent – meaning they are designed to protect against one type of Covid – and target a member of the XBB family.

those strains Covid descended from an omicron variant, which caused cases to rise to record levels early last year. It is one of the most immune-evasive strains to date.

The advisors also generally agreed that the new snapshots should specifically target a variant called XBB.1.5. The team only discussed the choice of the specific breed and did not vote on the matter.

XBB.1.5 accounts for nearly 40% of all Covid cases in the US as of early June, according to data From the Centers for Disease Control and Prevention. This percentage is slowly decreasing, and the incidence of related XBB.1.16 and XBB.2.3 variants is increasing.

The advisors note that XBB.1.5 looks more ideal for fall since vaccine makers Pfizer, Moderna and Novavax have already begun developing vaccines targeting the strain.

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

The FDA usually follows the advice of its advisory committees, but is not required to do so. It is not clear when the agency will make the final decision on the selection of the breed.

There is also uncertainty about the age groups administered by the FDA and CDC You will be advised to receive updated snapshots this fall.

But the committee’s recommendation is already a win for Pfizer, Moderna and Novavax — all of which were running early trials of their XBB.1.5 shots before the meeting.

“Novavax expects to be ready for commercial delivery of a monovalent protein-based XBB COVID vaccine this fall in line with today’s (Advisory Committee) recommendation,” said John Jacobs, the company’s president and CEO.

The United States is expected to shift vaccine distribution to the private sector this fall. This means that vaccine makers will start selling their new Covid products directly to healthcare providers and compete for commercial market share.

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

Covid cases and deaths Projection to new lows, governments have backed away from strict health mandates such as masking and social distancing and many people believe that The epidemic is over entirely.

But Dr. Peter Marks, the FDA’s chief of vaccines, said the agency is concerned that the United States will see another wave of Covid “during the time when the virus evolves further, population immunity weakens further and we move indoors for the winter.”

Periodically updated Covid vaccines to target a highly prevalent variant will restore protective immunity against the virus, said Dr. David Caslow, a senior official in the FDA’s Vaccines Division.

It’s a similar approach to how breeds are selected for Annual flu vaccine. Researchers are evaluating the circulating virus strains and estimating that they will be most prevalent during the coming fall and winter.

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

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

More than 40% of adults 65 and older have been boosted with these shots, while the rate among younger adults and children is between 18% and 20%.

Those boosters were bivalent, meaning they targeted the original strain of Covid and the omicron sub-variants BA.4 and BA.5.

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

Moderna has evaluated shots targeting XBB.1.5 and XBB.1.16 — another transmissible descendant of omicron, according to Rituparna Das, the company’s vice president of Covid vaccines.

Preclinical trial data in mice suggest that a monovalent vaccine targeting XBB.1.5 produces a stronger immune response against currently circulating XBB variants than an approved bivalent shot targeting BA.4 and BA.5, according to Das.

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

The overall protection against XBB strains, Das said, is likely due to fewer unique mutations among the variants, which means their makeup is similar.

There are only three unique mutations between the variants XBB.1.5 and XBB.1.16, according to Darren Edwards, lead for Moderna’s Covid-19 vaccine program. By comparison, there are 28 mutations between omicron BA.4 and BA.5.

This means that the immune response produced by the updated shot against the XBB variants will likely be similar, Edwards said, regardless of the specific variant it targets.

Pfizer also presented early trial data indicating that a monovalent vaccine targeting the XBB variant provides enhanced immune responses against the XBB family.

The company has provided specific timelines for delivering an updated vaccine, depending on which strain the FDA chooses.

Pfizer will be able to fire a monovalent shot targeting XBB.1.5 by July and a single-barrel shot targeting XBB.1.16 by August, according to Kenna Swanson, the company’s chief principal scientist.

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

Novavax hasn’t provided a specific timeline for delivering a snapshot targeting XBB.1.5, but it has indicated that the XBB.1.16 snapshot will take eight weeks longer.

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

The data also shows that the XBB.1.5 shot produces antibodies that prevent XBB.2.3 from binding to and infecting human cells, according to Dr. Philip Dubovsky, Novavax’s chief medical officer.

Dubovsky said the trial results support the use of a monovalent XBB.1.5 round in the fall.

Gap uses Novavax A protein-based technology, a decades-old method for fighting viruses used in routine vaccines against hepatitis B and shingles.