The FDA announced that it has authorized a third COVID-19 vaccine dose for people with weakened immune systems.

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The FDA announced that it has authorized a third COVID-19 vaccine dose for people with weakened immune systems. / Getty Images

The Food and Drug Administration is authorizing an additional dose of a COVID-19 vaccine for certain people with weakened immune systems caused either by disease, medical treatments or organ transplants.

The move comes after studies have shown these people may not have sufficient immunity to head off the more serious complications of COVID-19 after the standard vaccine regimen.

Late Thursday night, the FDA amended the emergency use authorizations for both the Pfizer-BioNTech and Moderna COVID-19 vaccines to allow for an additional dose for certain immunocompromised people, specifically, solid organ transplant recipients or those who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise. The CDC estimates the population to be less than 3% of adults.

"The country has entered yet another wave of the COVID-19 pandemic," said acting FDA Commissioner Dr. Janet Woodcock, noting that immunocompromised people are particularly at risk for severe disease. "After a thorough review of the available data, the FDA determined that this small, vulnerable group may benefit from a third dose of the Pfizer-BioNTech or Moderna Vaccines," Woodcock said.

The Centers for Disease Control and Prevention is convening a meeting of its immunization advisory committee Friday to consider the scientific evidence supporting the FDA's action and whether to recommend the additional dose for these people. The committee will also evaluate more broadly the need for a booster for people who are not immunocompromised.

Some countries have already started administering an additional dose to seniors, based on studies showing a decline in immunity over time. The committee is not scheduled to take any action on the broader question of boosters for the general population.

At a White House briefing Thursday, Dr. Anthony Fauci said there is a need for boosters for these people whose immune systems do not produce a strong response to the regular vaccine regimen. And while he believes that boosters will ultimately be needed for the general population, that time has not arrived.

"We believe sooner or later you will need a booster for durability of protection," he said. "But right at this moment, apart from the immunocompromised ... we do not believe that others, elderly or nonelderly, who are not immunocompromised need [another dose of] vaccine right at this moment."

He emphasized that the government was preparing for that need and would be "ready to do that and do it expeditiously." At the same time, with millions of people around the globe still waiting for their first dose, the World Health Organization is calling for a moratorium on booster shots to help make vaccine distribution more equitable.

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