US FDA authorises third COVID shot for people with weak immune system

US regulators on Thursday said transplant recipients and others with weakened immune systems can get an extra dose of the COVID-19 vaccine to better protect them as the delta variant continues to surge.

This was the first regulatory authorization in the U.S. for any kind of COVID-19 booster shot.

"The country has entered yet another wave of the COVID-19 pandemic, and the FDA is especially cognizant that immunocompromised people are particularly at risk for severe disease," acting FDA Commissioner Janet Woodcock said in a statement. "After a thorough review of the available data, the FDA determined that this small, vulnerable group may benefit from a third dose of the Pfizer-BioNTech or Moderna vaccines.

The announcement by the Food and Drug Administration applies to millions of Americans who are especially vulnerable because of organ transplants, certain cancers or other disorders. Several other countries, including France and Israel, have similar recommendations.

The FDA determined that transplant recipients and others with a similar level of compromised immunity can receive a third dose of the vaccines from Pfizer and Moderna at least 28 days after getting their second shot. The FDA made no mention of immune-compromised patients who received the single-dose Johnson & Johnson vaccine.

As per the words of Woodcock, the move will allow doctors to boost immunity in certain immunocompromised individuals who need extra protection from COVID-19. He also pointed out that other individuals who are fully vaccinated are adequately protected and do not need an additional dose of the COVID-19 vaccine at this time.

Meanwhile, a report by Al Jazeera states that FDA is closely monitoring data on studies of additional doses in immunocompromised people, according to an email from the agency that said it would share more information in the near future.

The new study of 120 transplant patients looked at the effects of a third dose that was given two months after the second. A month after the third shot, 55% of those who got it developed antibody levels likely to provide significant protection.

Among patients who got a placebo shot, rather than the third dose, just 18% showed the desired antibody levels, researchers at University Health Network in Toronto found. The findings from the Ajmera Transplant Centre at the network in Toronto were released Wednesday in the New England Journal of Medicine.