FDA Approves World's First Vaccine Against Respiratory Syncytial Virus

The US Food and Drug Administration (FDA) today announced approval of the first ever vaccine against respiratory syncytial virus (RSV). The vaccine (Arexvy, GSK) is approved for the prevention of RSV-associated lower respiratory tract disease (LRTD) in adults aged ≥60 years, according to the agency announcement.

According to GSK, the shot will be available for older adults prior to the 2023-2024 RSV season, which typically starts in the fall and peaks during the winter.

“Older adults, in particular those with underlying health conditions, such as heart or lung disease or weakened immune systems, are at high risk for severe disease caused by RSV,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, in the FDA announcement. “Today’s approval of the first RSV vaccine is an important public health achievement to prevent a disease which can be life-threatening.”

“Today marks a turning point in our effort to reduce the significant burden of RSV,” said Tony Wood, GSK chief scientific officer, in a GSK statement. “Our focus now is to ensure eligible older adults in the US can access the vaccine as quickly as possible.”

RSV-associated LRTD can cause life-threatening pneumonia as well as bronchiolitis in older adults. The Centers for Disease Control and Prevention (CDC) estimate that RSV leads to as many as 160 000 hospitalizations and up to 10 000 deaths annually among adults aged ≥65 years.

The FDA based its approval on data from the pivotal phase 3 AReSVi-006 trial. In the trial, which treated 25 000 participants with RSVPreF3 +AS01E and 25 000 with placebo, the vaccine showed statistically significant and clinically meaningful overall efficacy of 82.6% against RSV-LRTD in adults aged ≥60 years, satisfying the study’s primary endpoint. Further, efficacy was 94.6% in older adults with at least one underlying medical condition, such as certain cardiorespiratory and endocrine-metabolic conditions.

A range of prespecified secondary endpoints for the trial also were consistently positive including efficacy of 94.1% in patients with severe RSV-LRTD, and 93.8% in adults aged 70-79 years. Efficacy was consistent across RSV A and B subtypes (84.6% and 80.9%, respectively), findings consistent with the significant neutralizing antibody response seen against both variants, according to the company.

The vaccine was generally well tolerated with the most commonly reported side effects being injection site reaction, myalgias, headache, and arthralgias, all of which were mild-to-moderate in intensity and transient, according to the GSK announcement.

The CDC’s Advisory Committee on Immunization Practices at its meeting in June will discuss appropriate use of the vaccine in the US, including the potential scheduling, said GSK.

The FDA is requiring the company to conduct a postmarketing study to assess the signals of serious risks for Guillain-Barré syndrome and acute disseminated encephalomyelitis, according to the FDA statement.

FDA granted the GSK new drug application for the vaccine priority review in November 2022. On March 1, 2023, the FDA’s Vaccines and Related Biological Products Advisory Committee voted in favor of the safety and efficacy of GSK’s investigational RSV vaccine.