The US Food and Drug Administration (USFDA) on Tuesday approved Pfizer’s vaccine for use in pregnant individuals to prevent lower respiratory tract disease (LRTD) and severe LRTD caused by respiratory syncytial virus (RSV) in infants from birth through 6 months of age.
According to a statement issued by the US regulatory body, the vaccine, Abrysvo, is approved for use at 32 through 36 weeks gestational age of pregnancy.
Abrysvo is administered as a single dose injection into the muscle. The FDA approved Abrysvo in May for the prevention of LRTD caused by RSV in individuals 60 years of age and older, it stated.
“RSV is a common cause of illness in children, and infants are among those at highest risk for severe disease, which can lead to hospitalization. This approval provides an option for healthcare providers and pregnant individuals to protect infants from this potentially life-threatening disease,” said Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research in a statement.
RSV is a highly contagious virus that causes respiratory infections in individuals of all age groups. It is the most frequent cause of lower respiratory tract illness in infants worldwide. The virus is especially common in children, and most individuals can be expected to be infected with RSV by the time they reach two years of age.
According to USFDA, while RSV most often causes cold-like symptoms in infants and young children, it can also lead to serious LRTD such as pneumonia and bronchiolitis (swelling of the small airway passages in the lungs).
In infants and children, the risk of RSV-associated LRTD is highest during the first year of life. According to the Centers for Disease Control and Prevention, RSV is the leading cause of infant hospitalization in the U.S.
The safety and effectiveness of Abrysvo for immunization of pregnant individuals to prevent LRTD and severe LRTD caused by RSV in infants from birth through 6 months of age was evaluated in ongoing, randomized, placebo-controlled international clinical studies, USFDA stated.
The most commonly reported side effects by pregnant individuals who received Abrysvo were pain at the injection site, headache, muscle pain and nausea, it revealed.
In addition, although not commonly reported, a dangerous hypertensive disorder, known as pre-eclampsia, occurred in 1.8% of pregnant individuals who received Abrysvo compared to 1.4% of pregnant individuals who received placebo. In the safety studies, low birth weight and jaundice in infants occurred at a higher rate in the pregnant Abrysvo recipients compared to pregnant placebo recipients.
Moreover, the USFDA has asked the company to conduct post-marketing studies to assess the signal of serious risk of preterm birth and to assess hypertensive disorders of pregnancy, including pre-eclampsia. The application was granted Priority Review status and Fast Track and Breakthrough Therapy designations.
