Look out, GSK. Pfizer has its adult RSV vaccine approval and is raring to launch

About a month after GSK won the world's first approval for a respiratory syncytial virus (RSV) vaccine, rival Pfizer has followed suit.

Late Wednesday, the New York drugmaker said its Abrysvo won FDA approval to prevent against lower respiratory tract disease caused by RSV in adults 60 and older. Both companies are looking to launch their offerings ahead of the upcoming RSV season, which typically starts in the late fall.

Before the launch, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) will meet later this month to discuss recommendations for the newly approved RSV shots. Pfizer expects to make the vaccine available in the third quarter, should ACIP members put their support behind the vaccine. 

The FDA approved Abrysvo based on data from a phase 3 trial called RENOIR, which enrolled about 37,000 participants. In the study, the vaccine achieved 66.7% protection against RSV-associated lower respiratory tract illness. Against more severe illness, the vaccine's efficacy came in at 85.7%. The study is ongoing and is testing the shot during a second RSV season as well. 

In addition, Pfizer recently reported positive top-line results from a phase 3 study of Abrysvo co-administered with a seasonal inactivated flu vaccine in older adults. The company is further studying its RSV vaccine in other age groups and in those with underlying medical conditions.

Meanwhile, Pfizer also has a regulatory review underway for its RSV vaccine when used as a maternal immunization to protect infants from the respiratory virus. The FDA is set to make a decision on that application in August.

As for GSK, the company won approval for RSV shot Arexvy in adults 60 and older in early May. The company has started a marketing campaign called "Sideline RSV" and enlisted basketball star Earvin “Magic” Johnson to help raise awareness.

The RSV vaccine market is one of the pharma industry's next major battlegrounds, with analysts pegging the potential opportunity at more than $10 billion. Aside from Pfizer and GSK, Moderna has posted positive phase 3 vaccine results.

And partners Sanofi and AstraZeneca are hoping to win U.S. approval for their preventive antibody in the third quarter of 2023. The companies are positioning that drug for all infants to protect against their first RSV season. The antibody is approved in Europe as Beyfortus.