A review published Wednesday by the US Food and Drug Administration (FDA) found that a third dose of Pfizer’s COVID-19 vaccine boosts a person’s immunity to the virus. But the source added that current vaccines still provide sufficient protection to prevent severe illness.
The FDA is considering Pfizer’s request to offer a third shot of its vaccine, which the pharmaceutical company says is necessary because its efficacy decreases between six and eight months after the second dose. Pfizer submitted a preliminary study to the FDA that showed a third dose given to more than 300 people had increased their immunity levels three to five times higher than the previous injection.
Pfizer also cites a study from Israel, published Wednesday in the New England Journal of Medicine, which showed an 11-fold lower infection rate among people 60 years of age and older who received the third dose of the vaccine. About 1 million people took part in this study.
Pfizer has requested permission to offer a third dose while the much more transmissible delta variant of COVID-19 has sparked a dramatic new spike in infections, hospitalizations and deaths worldwide.
But the FDA in its review stated that recent research “indicates that COVID-19 vaccines licensed or authorized for use today still provide protection against severe COVID-19 illness and death in the US.”
A vaccine advisory committee at the US government’s drug regulator is scheduled to meet Friday to discuss whether the agency will grant Pfizer’s request. The committee’s recommendation was non-binding, meaning the FDA could approve a third dose of Pfizer even if the committee did not recommend it.
Both the FDA and the American Centers for Disease Control and Prevention (CDC) last month recommended a third shot of the Pfizer or Moderna vaccine for people with weakened immune systems.
The FDA meeting will come days after an international group of vaccine experts published an essay in the medical journal The Lancet against giving the general public the booster injections of the currently circulating vaccine. Experts say recent studies show vaccines now used worldwide continue to provide strong protection against viruses, including the delta variant, particularly from severe illness and hospitalization.
The essay’s authors include two key officials in the FDA’s office of vaccine reviewers who will leave their posts before the end of this year. The New York Times recently reported that Dr. Marian Gruber and Dr. Philip Krause is annoyed by the recent announcement by the Joe Biden administration that booster injections will be given to some Americans starting next month, well before the FDA has had enough time to properly review the data.
The authors state that modifying the vaccine to address certain COVID-19 variants is a better approach than administering an extra dose of the vaccine.
World Health Organization (WHO) Director General Tedros Adhanom Ghebreyesus has asked rich countries not to give booster vaccine shots for the rest of the year to ensure that low- and middle-income countries have more access to the vaccine. [uh/ab]