FDA approves Pfizer maternal RSV vaccine for infants

The Food and Drug Administration (FDA) has granted approval for Pfizer’s vaccine designed to protect infants from respiratory syncytial virus (RSV), a major cause of hospitalization among babies in the U.S. This vaccine uses maternal immunization, wherein pregnant mothers receive the vaccine to pass protective antibodies to their fetuses. Pfizer’s RSV shot is already approved and available for older adults.

This vaccine approval marks the second treatment approved by the FDA to prevent RSV in infants, and it’s the first vaccine of its kind. Pending a recommendation from the Centers for Disease Control and Prevention (CDC), Pfizer aims to make the vaccine available to the public by the end of October or the start of November, aligning with the onset of the RSV season.

Pfizer’s vaccine is administered to expectant mothers during the late second or third trimester of pregnancy. This single-dose vaccine prompts the production of antibodies in the mother, which are then transferred to the fetus, providing protection against RSV from birth through the first six months of life.

RSV typically leads to mild, cold-like symptoms, but it can be more severe in young children and older adults. The virus causes several hundred deaths in children under the age of 5 and affects 6,000 to 10,000 seniors annually, as reported by the CDC.

The FDA’s approval of Pfizer’s vaccine is grounded in data from a phase three trial, which showed the vaccine’s effectiveness in preventing severe RSV disease in newborns during their first 90 days of life was nearly 82%. The vaccine’s efficacy remained at around 70% during the first six months of a baby’s life. The FDA’s advisory panel had unanimously endorsed the vaccine’s effectiveness based on this data.

This vaccine approval has the potential to significantly impact public health by helping combat RSV during the upcoming season, particularly after a year of heightened RSV cases, largely attributed to a reduction in pandemic-related preventive measures that had previously helped curb its spread.