Pfizer Seeks Full U.S. Approval for Covid-19 Booster Shot

Pfizer Inc. and BioNTech SE are seeking full U.S. approval for a Covid-19 booster shot for people 16 and older, asking regulators to sign off on a third dose to quell a rise in infections among vaccinated people.

The companies announced Wednesday that they had started a rolling Biologics License Application with the Food and Drug Administration. Pfizer and BioNTech said they intend to complete submission of the application by the end of the week, bringing them one step closer to clearance for the additional shot.

The filing comes just days after the companies became the first to receive formal FDA approval for a Covid shot. The Pfizer-BioNTech vaccine has been a linchpin of the U.S. immunization effort, with more than 92 million people completing a two-dose regimen.

But a surge in virus cases caused by the highly transmissible delta variant has raised questions about how well the shot can protect vulnerable people such as organ-transplant recipients and seniors.

While certain immunocompromised individuals have already been cleared on an emergency basis to receive a third dose of the Pfizer-BioNTech and Moderna Inc. vaccines, the Biden administration has said it wants to begin giving more Americans booster doses starting next month.

A late-stage trial of 306 participants age 18 to 55 showed that a Pfizer-BioNTech booster dose given between 4.8 and 8 months after the two-dose regimen more than tripled protective antibodies against the original strain of the coronavirus, the companies said.

The third shot also demonstrated a favorable safety and tolerability profile, according to the companies, which will submit the data to a peer-reviewed journal.

Side effects in the first seven days were mild to moderate, the companies said, and included injection-site, muscle and joint pain, fatigue, headache, and chills. Adverse events, meanwhile, were consistent with clinical data from the two-dose regimen.

Pfizer shares were down 2.1% at 1:09 p.m. in New York trading, while BioNTech's American depository receipts were up 0.6%.

Booster Debate

Some scientists have questioned how urgently booster shots will be needed for the broader population, but the recent surge in infections has made the matter more pressing for health officials.

The seven-day moving average of new cases has reached about 141,000, the highest level since early February, according to data from the Centers for Disease Control and Prevention.

Acting Director of the FDA Janet Woodcock has said that the agency still needs to evaluate additional data before clearing a third-dose booster for people who aren't immunocompromised.

Earlier this month, Pfizer and BioNTech submitted early-stage data to the FDA showing that a third dose of their vaccine led to higher levels of protective antibodies when given eight to nine months after the initial regimen.

It is unclear how long it would take for the FDA to review the companies' approval application for a booster. The agency has vowed to move quickly in scrutinizing Covid-19 vaccines, but regulators are facing an increasingly large workload.

Earlier Wednesday, Moderna announced that it had completed the Biologics License Application for its own vaccine in people age 18 and older. Though the biotech is nudging forward toward a full approval for its two-dose regimen, it hasn't sought a clearance for a third booster shot.

A representative for the FDA didn't immediately return a request for comment.

The vaccines made by Moderna and health giant Johnson & Johnson are available under emergency-use authorizations, a temporary clearance granted amid public-health crises. Also on Wednesday, J&J said that early trial data showed a booster dose for its single-shot vaccine substantially increased the shot's ability to ward off disease.

Pfizer and BioNTech said they will also share the late-stage booster data with the European Medicines Agency and other regulatory authorities in coming weeks.

(Updates throughout with additional context and detail)

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