WASHINGTON—The Food and Drug Administration plans to develop speedy means of evaluating possible booster shots for Covid-19 vaccines to ensure that they will work against new variants, the agency’s acting commissioner said Thursday.
Dr. Janet Woodcock wasn’t specific about what standards the FDA will use to assess the possible booster shots but said the agency will address these questions in published guidelines over the next few weeks.
“If variants emerge that the vaccines have poor efficacy against, we will need to go through these quickly,” she told reporters Thursday evening. She said that full clinical studies of 30,000 patients or more—the sort of large clinical trial used to authorize vaccines so far—would be too time-consuming.
Dr. Woodcock said there hasn’t been any determination that boosters will be needed.
“With current vaccines, we feel that, against any variants we have seen we have a fair amount of confidence they will provide good protection,” she said. But, she added, “We must prepare for all eventualities. The situation could change, and it could change pretty rapidly.”
Currently, the FDA has authorized two Covid-19 vaccines. One is from Moderna Inc., the other from a partnership of Pfizer Inc. with Germany’s BioNTech SE.
Late Thursday, Johnson & Johnson said it submitted an application to the FDA seeking emergency-use authorization for its single-dose Covid-19 vaccine candidate. The FDA said it will hold a public hearing on February 26 to evaluate this vaccine.
Variants of the new coronavirus have emerged in Britain, South Africa and elsewhere, and some have begun to be detected in the U.S.
Despite the need to react quickly, said Dr. Woodcock, she and other agency officials are inclined to insist that any booster shots, if necessary, be evaluated by an advisory committee of independent experts in a public hearing.
“I think it would be very wise if we have the time to provide public transparency,” she said. “Having a public discussion will help.”
Many vaccine makers, including Moderna and the Pfizer/BioNTech partnership, are designing new shots that would target variants, especially the one first identified in South Africa and detected elsewhere, including the U.S.
Vaccines from Johnson & Johnson and Novavax Inc. showed less effectiveness in studies in South Africa once the variant emerged there.
Dr. Woodcock also said that the principal diagnostic tests used in the U.S. so far “are performing adequately” against virus variants.
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