Pfizer says RSV shot to protect infants may be available by 2023-24 cold and flu season

Pfizer’s vaccine to protect infants from RSV may be approved before the next cold and flu season, the company said on Tuesday.

Regulators granted RSVpreF, also known as PF-06928316, a priority review for the prevention of medically attended lower respiratory tract illness (MA-LRTI) caused by RSV in infants. The shot would be administered during pregnancy to protect infants from birth to 6 months old.

In this case, Pfizer defined medically attended illness as being sick enough to warrant a trip to the doctor, on top of at least one sign of severe illness, such as fast breathing or low oxygen. The news comes just a few months after RSVpreF swung another priority review for adults over age 60.

Pfizer is expecting a decision in the adult population in May and in pregnant women for infants by the end of August.

If approved, the company anticipates supply to be ready in Q3, with “sufficient RSVpreF supply available for both a maternal and older adult indication ahead of the 2023/24 RSV season,” a spokesperson told Endpoints News. 

That puts Pfizer a few steps ahead of Moderna, which said last month that it expects to file an application in the first half of this year for mRNA-1345, its mRNA-based RSV shot for adults 60 years and older. The candidate is still in a Phase I trial for pediatric use.

“We’re going to be filing as fast as we can,” CEO Stéphane Bancel told Endpoints News after unveiling positive data in older adults last month.

GSK beat Pfizer to a BLA submission for its RSV vaccine in older adults back in November, scoring a PDUFA date of May 3. However, GSK halted enrollment and vaccination for its maternal vaccine last February to “better understand safety data.”

Phil Dormitzer

“We continue to collect data and further analysis is ongoing. We are committed to share updates as they become available. Our RSV Older Adult program continues as planned and remains on track following release of phase III data and regulatory filings,” Phil Dormitzer, head of vaccine R&D at GSK, said in an email on Wednesday.

The FDA is hosting advisory committee meetings next week to discuss RSV shots from both Pfizer and GSK. Sanofi’s RSV antibody Beyfortus, jointly developed by AstraZeneca, is also under FDA review with an expected decision in the third quarter of this year.

“We’re getting ready to launch Beyfortus for the next RSV season as soon as we get the license and ACIP recommendation,” Sanofi’s executive VP of vaccines Thomas Triomphe said on a recent quarterly call.

Annaliesa Anderson

Back in November, Pfizer reported topline Phase III results suggesting that RSVpreF was 81.8% effective against severe MA-LRTI in infants through the first 90 days, and 69.4% effective at 6 months.

“If approved, RSVpreF would help protect infants at their first breath from the devastating effects of this infectious disease, which though well-known, has been particularly evident throughout this RSV season,” Annaliesa Anderson, senior VP and CSO of vaccine R&D at Pfizer, said in a news release.

fda