The FDA granted a "priority review" designation for the companies’ Biologics License Application (BLA) completed in May, which included late-stage trial data on safety and efficacy up to six months post-second dose. Findings released in April stemming from 927 confirmed cases of symptomatic COVID-19 (850 cases in the placebo group versus 77 in the vaccinated group) suggested the vaccine was 91.3% effective up to six months after the second dose.
The vaccine's protection against severe COVID-19 ranged from 95.3% to 100% depending on definitions used by the FDA and Centers for Disease Control and Prevention (CDC), respectively. The vaccine's safety has been studied in over 44,000 participants aged 16 and up, and six months' worth of follow-up data is available for over 12,000 vaccinated participants post-second dose, "demonstrating a favorable safety and tolerability profile" and "no serious safety concerns were observed," the companies previously said.
A spokesperson at the FDA told Fox News the agency expects to complete the review "far in advance" of the January target date.
Pfizer CEO Albert Bourla touted the results, including high protection against a concerning viral variant first detected in South Africa; nine cases of COVID-19 cropped up in the placebo group in a study involving 800 total participants in South Africa, translating to a vaccine efficacy of 100%. Six of the nine cases were tied to the viral variant after sequencing. The vaccine was less protective against the variant compared to the original strain, but the company and public health officials have said the vaccine remains highly effective.
The FDA has not yet approved any COVID-19 vaccine, but has given emergency use authorization (EUA) to vaccines developed by Pfizer-BioNTech, Moderna and Johnson & Johnson.
Pfizer has also signaled its intention to file for emergency use authorization for a COVID-19 booster shot, but the FDA and CDC said fully vaccinated Americans "do not need" an extra dose at this time. The health agencies said the U.S. "is fortunate to have highly effective vaccines that are widely available" to eligible populations. Nevertheless, a panel of independent experts advising the CDC plans to consider additional doses of the COVID-19 vaccine in a small fraction of the population with weakened immune systems.
The Advisory Committee on Immunization Practices (ACIP) plans to convene on July 22 to discuss "clinical considerations for additional doses in immunocompromised individuals," according to a draft agenda posted ahead of the meeting.
The National Institutes of Health defines immunocompromised patients as those with "a reduced ability to fight infections and other diseases," potentially caused by conditions like "AIDS, cancer, diabetes, malnutrition, and certain genetic disorders" or medicines or treatments like chemotherapy and organ transplants.
Some evidence has indicated immunocompromised individuals, who account for about 2.7% of the country’s population, mount a diminished protective immune response, even after two doses of vaccine. More specifically, one study showed 7-27 days after a second Pfizer dose, there was 75% protection against symptomatic COVID-19 among immunosuppressed patients, compared with 94% overall. The patients also saw less protection against infection at 71% versus 90% overall, after two Pfizer doses.
Fox News' Alexandria Hein contributed to this report.