FDA authorises second booster of Pfizer/BioNTech and Moderna COVID shots

The US Food and Drug Administration (FDA) authorised a second booster dose for people aged 50 years and older of the two most commonly used COVID-19 vaccines, citing data showing waning immunity and the risks posed by Omicron variants of the virus.

The agency said the new boosters – a fourth round of shots for most vaccine recipients – of the Pfizer Inc/BioNTech SE and Moderna Inc vaccines are to be administered at least four months after the previous dose. They are intended to offer more protection against severe disease and hospitalisation.

The FDA also authorised the second booster dose of the vaccines for younger people with compromised immune systems – those aged 12 years and older for the Pfizer/BioNTech shot, and 18 years and older for Moderna’s.

The authorisation comes as some scientists have raised concerns about the highly contagious and newly predominant BA.2 Omicron subvariant, which has driven up COVID-19 cases in other countries.

The FDA said it looked at data from a relatively small, ongoing clinical trial in Israel to help make its decision. In addition, safety data from more than 700,000 people who received second boosters in Israel revealed no new concerns, the agency said.

Scientists and officials have debated for months if and when an additional booster shot would be needed as they parsed data on how long protection from the vaccines and boosters would last.

“It’s not clear that now is the right time for people to get a fourth dose,” Dr William Moss, Executive Director, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, said.

It is also unclear whether young, healthy people will need a fourth shot. The study of Israeli healthcare workers cited by the FDA suggested that the fourth dose added little additional protection in the age group.

Edits by EP News Bureau