CDC Recommends Maternal RSV Vaccine for Protection of Newborns

In an ongoing effort to reduce respiratory syncytial virus (RSV) in the infant population, the CDC has now recommended the Pfizer bivalent RSVpreF (Abrysvo) vaccine be given to pregnant women. The federal agency recommends seasonal administration of 1 dose of this RSV vaccine for pregnant people during weeks 32 through 36 of pregnancy. The vaccine has been shown to reduce the risk of RSV hospitalization for babies by 57 percent in the first six months after birth.

“This is another new tool we can use this fall and winter to help protect lives,” CDC Director Mandy Cohen, MD, said in a statement.

What the Data Showed

Last month the FDA approved the Pfizer RSVpreF vaccine based on the data from the randomized, double-blind, placebo-controlled phase 3 clinical trial MATISSE (NCT04424316), which evaluated efficacy, safety, and immunogenicity of the vaccine against LRTD and severe LRTD due to RSV in infants born to healthy individuals who were vaccinated during pregnancy. The trial, which was conducted in 18 countries over 4 RSV seasons, followed infants for up to 2 years.

A total of 3682 maternal participants received the RSVpreF vaccine and 3676 received placebo, and the investigators subsequently evaluated, respectively, 3570 and 3558 infants.

The investigators determined that the successful criterion for vaccine efficacy was met. Medically attended severe lower RSV-associated lower respiratory tract illness occurred within 90 days after birth in 6 infants of women in the vaccine group and 33 infants of women in the placebo group, for a vaccine efficacy of 81.8%.

Another Prevention Tool for Infants and Newborns

This latest recommendation from the CDC comes 1 month after the agency’s recommendation for the monoclonal antibody, nirsevimab. Specifically, CDC recommended nirsevimab be administered as an immunization for all infants younger than 8 months, born during, or entering, their first RSV season (typically fall through spring) receive 1 dose of nirsevimab for protection against the virus. In addition, for a small group of children between the ages of 8 and 19 months who are at increased risk of severe RSV disease, such as children who are severely immunocompromised, a dose is recommended in their second season.

Nirsevimab is manufactured by Sanofi and AstraZeneca. There are now 2 prevention tools for clinicians to protect the youngest, most vulnerable population.

“I encourage parents to talk to their doctors about how to protect their little ones against serious RSV illness, using either a vaccine given during pregnancy, or an RSV immunization given to your baby after birth,” Cohen said.