The U.S. Food and Drug Administration has authorized an optional second round of COVID-19 booster shots for anyone 50 and older who wants extra vaccine protection.
The authorization for the Pfizer-BioNTech and Moderna shots comes as the new omicron subvariant continues to rapidly spread overseas and raise concern that it may lead to a similar increase in infections in the U.S. COVID-19 cases, hospitalizations and deaths have been falling in the U.S. in recent weeks.
The new subvariant, BA.2, is more transmissible than the original omicron variant, which caused a record number of cases in the U.S. in January. It does not appear to be more severe in terms of illness, however.
A second booster shot is not being recommended to everyone over the age of 50 at this time.
While requesting authorization for a second booster shot, specifically for those aged 65 and older, Pfizer-BioNTech said its third vaccine dose begins to lose its effectiveness in preventing symptomatic COVID-19 and severe disease after three to six months. Data published by the Centers for Disease Control and Prevention last month similarly found that booster shots lose a great deal of effectiveness after four months.
Pfizer also cited Israeli studies that found that coronavirus infections were two times lower, and severe illness was four times lower, among people who received a second booster dose, compared to someone who’d received only one booster shot.
Moderna told the FDA that authorizing these shots would “provide flexibility” to the CDC and medical providers, as they mean health officials can offer extra protection on an individual basis, “including for those at higher risk of COVID-19 due to age or comorbidities.”