Pfizer asks US regulators to expand Covid booster shot to all adults

Trial findings demonstrate relative vaccine efficacy of 95% when compared with those without booster, firm says

A healthcare worker prepares a Pfizer-BioNTech coronavirus vaccine at a mobile vaccine clinic in the US last month. Photograph: Alisha Jucevic/The New York Times

A healthcare worker prepares a Pfizer-BioNTech coronavirus vaccine at a mobile vaccine clinic in the US last month. Photograph: Alisha Jucevic/The New York Times


Pfizer said it had asked US regulators to expand access to its Covid-19 booster shot to all adults, and submitted data from a large trial showing that an additional dose is safe and highly effective at preventing infection.

The pharmaceutical giant and partner BioNTech SE said in a statement on Tuesday that they had requested that the Food and Drug Administration amend the shot’s existing emergency-use authorisation and extend eligibility for a third dose to everyone 18 and older.

The partners shared data from a more than 10,000-person late-stage study evaluating the safety and efficacy of a booster dose administered to participants who had received two doses at least 6 months prior. The trial launched in the US, Brazil and South Africa among people 16 and older this past summer as cases caused by the delta variant surged.

Findings from the trial demonstrated a relative vaccine efficacy of 95 per cent when compared with those who didn’t get a booster, the companies said.

Pfizer shares were down 1.5 per cent at 2.51 pm in New York on Tuesday. BioNTech’s American depositary receipts were down 5.5 per cent.

Regulators first cleared a Pfizer booster shot in September for people 65 and older; individuals 18 to 64 who are at high risk of developing severe Covid-19; or adults whose work or living conditions put them at high risk of serious complications from the disease. The FDA and its advisers signed off on this decision after evaluating clinical trial data that showed the booster prompted a strong immune response. At the time, they didn’t have efficacy data in hand.

Results shared

In late October, the vaccine partners shared early results from the 10,000-person trial demonstrating that the third dose was 95.6 per cent effective against symptomatic cases of Covid-19. Pfizer and BioNTech are the only companies to have reported efficacy data from a randomised trial of a booster shot.

The Pfizer-BioNTech vaccine regimen is initially given in two doses three weeks apart. The booster should be administered at least six months after the first round of injections, according to the FDA.

Booster shots could be a crucial tool for fending off a potential winter wave of infections. Regulators have authorised additional doses for all three of the vaccines available in the US, and experts have been especially focused on protecting more vulnerable groups such as the elderly and those with compromised immune systems.

Some 24.8 million Americans had received an additional Covid-19 shot as of Tuesday, according to the Centers for Disease Control and Prevention.

While the booster campaign has been ramping up, there are signs that a recent decline in infections is ending. Cases soared over the summer, fueled by the delta variant, and then declined through much of September and October. But now, cases are beginning to plateau, and public-health officials fear that the holiday season and colder weather could nurture a new wave of illness.

Pfizer had initially asked regulators for a broader clearance for boosters earlier in the year. But the emergency clearance granted by the FDA left the door open for consideration of wider use of the shots as more data on safety and efficacy became available. – Bloomberg