FDA wants to simplify use and update of Covid-19 vaccines


The US Food and Drug Administration wants to simplify the Covid-19 vaccination process to look more like what happens with the flu vaccine, according to documents posted online Monday. This could include streamlining vaccine composition, vaccination schedules and periodic updates of Covid-19 vaccines.

The FDA said it plans to evaluate circulating strains of the coronavirus at least once a year and decide in June which strains to select for the fall season, much like the process for updating annual vaccines against influenza.

Going forward, the agency said, most people may only need a single dose of the latest Covid-19 vaccine to restore protection, regardless of how many vaccines they have. previously received. Two doses may be needed for people who are very young and unexposed, who are elderly or have weakened immune systems, according to the FDA’s briefing document for its vaccine advisors.

The agency is urging a move to a single vaccine composition rather than a combination of monovalent vaccines – which are currently used for primary injections and target only one strain – and bivalent vaccines – which are currently used for booster doses and target more than one strain.

FDA briefing materials do not specify whether the annual vaccine would contain a single strain, two strains, or more. The annual flu vaccine immunizes against four strains.

“This simplification of vaccine composition should reduce complexity, decrease vaccine administration errors due to the complexity of the number of different vial presentations, and potentially increase vaccine compliance by allowing for clearer communication,” said the FDA.

The agency’s independent vaccine advisers, the Vaccines and Related Biologics Advisory Committee, are due to meet on Thursday to discuss the future of Covid-19 vaccination regimens and will be asked to vote in favor. find out if they recommend certain parts of the FDA plan.

Vaccine experts had mixed responses.

Dr. Gregory Poland of the Mayo Clinic, a former member of the FDA’s expert advisory panel, said the first thing to do is define what he expects the annual vaccination to achieve.

“They’re going to have to decide what the purpose of using current vaccines is,” said Poland, who studies how the body responds to vaccines. “If it’s to prevent serious illness and death, we’re already there.”

Before considering switching to annual boosters, he would like to see data on the effectiveness of current updated boosters compared to the latest Omicron sub-variants.

“The data that keeps coming out regarding efficacy predates the BQ and XBB subvariants,” Poland said.

The committee must also demand full transparency from the FDA and drugmakers when weighing its decisions, he said. He was very concerned that the agency had not shared all the data it had on bivalent boosters with the advisory committee in June.

Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, said he sees the annual update plan as a balance between what science says is needed to fight the virus and what which is really handy.

“I think it’s a balance, trying to do what the science says, which is the need for adaptability and flexibility. Yet companies are unlikely to be able to make this change more quickly. once a year,” he said.

But this plan also has some weaknesses, he notes. Annual updates are fine as long as the virus continues to evolve gradually, based on viruses that were circulating previously. But he wonders if the world has enough genomic surveillance to catch a radically different variant that pops up from left field, like Omicron did.

“We don’t have surveillance mechanisms in place globally. We don’t have genomic sequencing in place globally. We don’t have the carefully orchestrated dance that took decades to unfold. build for flu surveillance rather than coronavirus surveillance,” Hotez said.

Dr. John Wherry, director of the Institute of Immunology at the University of Pennsylvania, has studied how second-line immune defenders called T cells resist strains of coronavirus

The answer is that things are looking pretty good. Even though our antibody levels drop about three months after a boost, our T cells seem to stick around longer – up to nine months so far – and are thought to be the component of immunity that protects against serious consequences such as hospitalization. And the dead.

Even though there doesn’t appear to be much measurable decline in T-cells over time, Wherry says, he supports the FDA’s plan for an annual Covid-19 vaccine.

“Recommending vaccines regularly as part of your routine health care is something we should be doing,” he said. “A yearly boost with the vaccine will actually help make your T-cells fitter, keep them up to date, and keep them able to protect us behind the antibodies.”

This means that the boosters should provide certain short-term and long-term benefits.


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