Four weeks after the Food and Drug Administration greenlit GSK’s respiratory syncytial virus (RSV) vaccine for people over the age of 60, the agency approved Pfizer’s vaccine. 

The FDA based its decision to approve Abrysvo on Pfizer’s Phase 3 clinical trial data, which was published in the New England Journal of Medicine (NEJM) in April.

The pharma giant said Abrysvo prevented RSV-associated lower respiratory tract illness and acute respiratory illness in adults over the age of 60 without evident safety concerns, with a reported efficacy of 67%.

Annaliesa Anderson, PhD, SVP and chief scientific officer of vaccine research and development at Pfizer, said the FDA’s decision is a “monumental step forward” in the company’s efforts to prevent RSV infections in high-risk populations.

“Abrysvo will address a need to help protect older adults against the potentially serious consequences of RSV disease,” Anderson said in a statement. “We are extremely grateful to the clinical trial participants, study investigator teams and our dedicated Pfizer colleagues for their roles in making this vaccine available.”

The Pfizer data published in NEJM was released one month after the Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 7 to 4 on both safety and effectiveness in support of the treatment. 

Going forward, the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices will meet on June 21 to discuss recommendations for appropriate use of RSV vaccines in older adults.

Pending results of that meeting, Pfizer said it anticipates supply availability in Q3 2023 ahead of the start of the 2023/24 RSV season this fall.

Pfizer is now the second pharma company to get its RSV vaccine across the FDA finish line.

GSK’s Arexvy, which received unanimous support from VRBPAC for its effectiveness and also received a 10 to 2 vote in support of its safety profile, ultimately received approval from the FDA during the first week of May. 

The decision gave GSK a month-long headstart on both Pfizer and Moderna, which saw its vaccine receive a breakthrough designation from the FDA at the end of January. The biotech is still aiming to file a license application for regulatory approval in the first half of the year.

Meanwhile, GSK said it intends to launch Arexvy prior to the start of the upcoming RSV season. The British pharma giant has already doubled down its advertising effort around RSV, debuting its Cut Short by RSV ads and reenlisting NBA Hall of Famer Earvin “Magic” Johnson for another series of commercials.