Pfizer asks FDA to clear another booster for older adults

[NEW YORK] Pfizer said it has asked US regulators for clearance of an additional Covid-19 booster shot for seniors, in a bid to protect vulnerable adults as immunity provided by the first 3 doses wanes.

The New York-based drugmaker and its German partner BioNTech said on Tuesday (Mar 15) that they have sought an emergency-use authorisation from the Food and Drug Administration (FDA) for a second booster of their vaccine, Comirnaty, for people 65 and older who have already received a booster of any of the authorised Covid-19 vaccines.

Pfizer and BioNTech said they submitted data to the FDA from Israel, which began offering a fourth shot to older people and healthcare workers last year as the Omicron variant was circulating. The real-world data showed a fourth shot given at least 4 months after the third reduced the rate of infection and severe illness compared to those who were given just 1 booster shot, according to an analysis of Israeli Ministry of Health records for over 1.1 million adults 60 and older with no known history of Covid infection.

The vaccine partners also submitted data from a study of healthcare workers in Israel, which found that staff who'd received a fourth dose of the vaccine had greater levels of Covid-fighting antibodies, including against Omicron than those who had received 3 doses.

On Mar 13, Pfizer chief executive officer Albert Bourla said in an interview with CBS that a fourth dose of the vaccine was needed "right now", as protection from the first 3 shots had waned.

In the US, people 12 and older can receive a single booster dose of the Comirnaty vaccine if they've already completed the 2 doses Pfizer-BioNTech regimen. Among those who initially got a shot developed by Moderna or Johnson & Johnson, only those 18 and older can get a Comirnaty booster.

People who received a third dose generally fared better against the Delta and Omicron variants than people who received only 2 doses, according to studies the Centers for Disease Control and Prevention (CDC) released earlier this year.

While Covid-19 cases have dropped sharply from their winter peak, there are signs that another increase in infections could be in the cards in the coming weeks. More than a third of CDC wastewater sample sites in the US showed rising virus trends earlier this month.

Pfizer is also studying an Omicron-specific vaccine and a hybrid shot that would target Omicron along with earlier variants. The company is expected to report data on these efforts in April.

The CDC recommends some immunocompromised people get a 3-dose primary series of mRNA shots and a fourth shot as a booster. BLOOMBERG