• The Food and Drug Administration approved a vaccine made by Pfizer that protects adults ages 60 and older from respiratory syncytial virus, a common pathogen that kills and hospitalizes thousands of seniors annually.
• The single-dose vaccine was 67% to 86% effective at preventing illness from RSV.
• The approval comes weeks after the FDA cleared a similar shot made by GSK.

The Food and Drug Administration on Wednesday approved a vaccine made by Pfizer that protects adults ages 60 and older from respiratory syncytial virus, a common pathogen that kills and hospitalizes thousands of seniors every year.

Pfizer, in a statement Wednesday, said it expects to have supply available in the third quarter of this year ahead of the RSV season. The Centers for Disease Control and Prevention's committee of independent advisors will meet on June 21 to make recommendations on the use of the vaccine.

The approval of Pfizer's vaccine comes just weeks after the FDA cleared a similar shot targeting RSV that is made by GSK.

The two FDA authorizations within just a month represent a historic milestone for public health, after decades of failed efforts to develop vaccines for the virus.

RSV causes mild symptoms similar to a cold in most people but older adults face a higher risk of severe illness.

The virus kills 6,000 to 10,000 older adults and hospitalizes 60,000 to 160,000 of them every year, according to the federal Centers for Disease Control and Prevention.

RSV also circulates at the same time as Covid and flu.

The combined burden of the three viruses put substantial pressure on the health-care system late last year. The two new RSV vaccines from Pfizer and GSK could help ease some of that pressure this fall.

Pfizer's shot is administered as a single 120-microgram dose.

The vaccine was about 67% effective against lower respiratory tract illness with at least two signs or symptoms, and about 86% effective against this illness with three signs or symptoms, according to clinical trial results.

The FDA's committee of independent advisors endorsed Pfizer's vaccine in February. But several members of the panel had voiced safety concerns about the shot.

Two participants in Pfizer's clinical trial developed Guillain-Barre syndrome after receiving the vaccine. Guillan-Barre is a rare neurological disorder with symptoms ranging from brief weakness to paralysis.

The FDA views the two Guillain-Barre cases as possibly linked to the vaccine. The agency has asked Pfizer to conduct a post-approval safety study to monitor for the disorder.

Pfizer has also developed a vaccine to protect newborns from RSV.

The FDA's advisors backed that shot in a meeting earlier this month. The FDA is expected to make a final decision on that vaccine in August.