The agency’s new guidance will speed the development of vaccines that protect against more contagious variants of the coronavirus.
“The emergence of the virus variants raises new concerns about the performance of these products,” Dr. Woodcock said in a statement Monday. “We want the American public to know that we are using every tool in our toolbox to fight this pandemic, including pivoting as the virus adapts.”
Moderna has already begun developing a new version of its vaccine that could be used as a booster shot against a virus variant that originated in South Africa, known as B.1.351, which seems to dampen the effectiveness of the existing vaccines.
Still, the guidance did not appear to be written with the assumption that new vaccines were imminent, or would be needed at all. Despite the recent indications that some variants — and particularly B.1.351 — make the currently authorized vaccines less effective, the shots still offer protection and appear to greatly reduce the severity of the disease, preventing hospitalizations and death.
Asked at a news briefing on Monday afternoon how much the variants would need to spread before updated vaccines were necessary, Dr. Woodcock did not give any specific criteria. “We need to anticipate this and work on it so that we have something in our back pocket before the threshold is upon us,” she said.
Dr. Peter Marks, the top vaccine regulator at the F.D.A., said at the news briefing that studies would include a “few hundred” people and last several months.
Volunteers will also be monitored carefully for side effects. The agency said the testing could be done in a single age group and then extrapolated to other age groups.
The guidance also encouraged the use of animal studies to support the case for modified vaccines, in case immune response studies come up with ambiguous conclusions.
Some other vaccines are regularly updated in a similar way. Because the influenza virus evolves rapidly from one year to the next, vaccine developers have to come up with new recipes annually.
The newly tweaked Covid-19 vaccines would be authorized under an amendment to the emergency authorization granted to the original vaccine, regulators said.
Source: New York Times