FDA Says Pfizer COVID-19 Vaccines Still Effective, Boosters May Not Be Needed

A nurse prepares a Pfizer BioNTech COVID-19 vaccination in Los Angeles, Calif., on Aug. 23, 2021. (Lucy Nicholson/Reuters)

The Food and Drug Administration (FDA) on Wednesday said that agency-authorized COVID-19 vaccines currently provide protection against death and severe disease and may not require additional boosters, coming after vaccine maker Pfizer submitted data saying that its vaccine’s efficacy is eroding over time.

In findings released online, the FDA analyzed data submitted by Pfizer as part of their request to authorize a booster shot, or a third dose, of the vaccine to individuals aged 16 and older in the United States. The agency did not make a definitive statement on whether to support booster shots at this time, adding that regulators have not reviewed the available data.

“There are many potentially relevant studies, but FDA has not independently reviewed or verified the underlying data or their conclusions,” the FDA wrote (pdf) in a 23-page document published online. “Some of these studies, including data from the vaccination program in Israel, will be summarized during the September 17, 2021 [Vaccines and Related Biological Products Advisory Committee] meeting.”

Some studies, they said, have indeed shown the Pfizer mRNA vaccine has waning efficacy against the Delta variant or symptomatic infection. However, other studies have not, the FDA said.

“Overall, data indicate that currently U.S.-licensed or authorized COVID-19 vaccines still afford protection against severe COVID-19 disease and death in the United States,” FDA researchers wrote.

Biden administration officials late last month said in a news conference that they are aiming for a Sept. 20 rollout for boosters, although they cautioned that their plan is contingent on whether the doses are approved by the FDA. A panel of outside observers will review the FDA’s report on Friday and will analyze the Pfizer analysis and other information to determine whether boosters are needed for the general population.

If the panel recommends boosters, the FDA could distribute the doses within a few days.

In August, the FDA fully approved the Pfizer-BioNTech vaccine for people aged 16 and older. Vaccines made by Moderna, which uses mRNA technology like Pfizer, and Johnson & Johnson are still being distributed under the agency’s emergency use authorization.

During its presentation to the FDA, which was uploaded on the agency’s website, Pfizer argued that data from the United States and Israel suggests its mRNA vaccine efficacy is dropping over time, warranting the need for boosters.

“Real-world data from Israel and the United States suggest that rates of breakthrough infections are rising faster in individuals who were vaccinated earlier in the vaccination campaigns compared to those who have been vaccinated more recently,” Pfizer said.

For its conclusion, the German-based pharmaceutical giant cited a study from healthcare giant Kaiser Permanente that suggested protection against COVID-19 infection dropped from 88 percent in the first month of getting the second dose to 47 percent after five months of inoculation.

Earlier this week, a study that included two departing FDA officials said they do not recommend booster shots and said that possible side effects from them could outweigh the benefits.

“Even if boosting were eventually shown to decrease the medium-term risk of serious disease, current vaccine supplies could save more lives if used in previously unvaccinated populations,” the authors wrote.

Pfizer has not responded yet to a request for comment.