Single-Dose RSV Vaccine Protects Immunocompromised Adults

Pfizer Inc. today announced positive top-line safety and immunogenicity results from substudy B of the ongoing pivotal Phase 3 clinical trial.

The trial is evaluating two doses of the ABRYSVO™ vaccine in immunocompromised adults aged 18 and older at risk of developing severe respiratory syncytial virus (RSV)- associated lower respiratory tract disease.

ABRYSVO was well-tolerated during the trial, showing a safety profile consistent with findings from other vaccine studies.

While the company evaluated two doses, a single 120 µg dose of ABRYSVO generated a strong neutralizing response against both subtypes of RSV, RSV-A, and RSV-B across all cohorts and age groups in the study.

Pfizer plans to share these findings at an upcoming scientific conference, publish them in a peer-reviewed scientific journal, and submit the data to the regulatory agencies for review.

“Immunocompromised adults, such as patients with cancer or autoimmune disorders, have a substantially increased risk of experiencing severe complications from RSV, yet there are currently no vaccines approved for those aged 18 to 59 in the U.S.,” said Annaliesa Anderson, Ph.D., Senior Vice President and Chief Scientific Officer, Vaccine Research and Development, Pfizer, in a press release on August 12, 2024.

“We are encouraged by the positive top-line data from this study, which provide important evidence that ABRYSVO has the potential to address a significant unmet need in this vulnerable population.”

These most recent data in immunocompromised adults build on the body of evidence supporting the profile of ABRYSVO in high-risk adults. 

As of early August 2024, three RSV vaccines have been approved for use in the U.S., and several vaccine candidates are conducting late-stage studies.

Additionally, the U.S. CDC reported on August 9, 2024, that RSV sections were generally low, except for the state of Florida.