The Food and Drug Administration on Monday approved an injectable drug that can protect children up to 2 years old from respiratory syncytial virus.
The drug, a monoclonal antibody injection called Beyfortus, can be given as a single injection to newborns and infants during their first RSV season. Children up to age 2 who are vulnerable to severe infections from the respiratory virus — such as those with congenital heart disease or premature babies with long-term breathing and lung problems — can receive a second dose during their second RSV season.
The Centers for Disease Control and Prevention's Advisory Committee for Immunization Practices will meet to discuss recommendations about who should receive the shots. Once the CDC director, Dr. Mandy Cohen, signs off on the panel’s recommendation, the injections can be distributed to the public.
An independent advisory committee to the FDA unanimously voted last month to recommend Beyfortus for newborns and infants, and it voted 19-2 in favor of second doses for high-risk children up to age 2.
Beyfortus acts similarly to a vaccine, but instead of prompting the immune system to develop antibodies to the virus — what's known as "active immunization" — it delivers the antibodies directly to the bloodstream via so-called passive immunization.
Most children are infected with RSV by age 2. The virus causes a lower respiratory illness that is generally mild, but in serious cases can lead to pneumonia or bronchiolitis, which inflames airways and clogs them with mucus.
Older adults and babies under 6 months old are particularly susceptible to severe RSV. The virus leads to up to 80,000 hospitalizations and up to 300 deaths a year among children under age 5 in the U.S.
Beyfortus is made by drugmaker AstraZeneca in partnership with Sanofi, which is responsible for marketing the drug. Sanofi said in a statement Monday that the injections would be available in the U.S. ahead of the 2023-2024 RSV season.
RSV infection rates typically rise in the fall and peak in the winter, but last year’s season — which resulted in a dramatic spike in severe illnesses that overwhelmed children’s hospitals — started in June and peaked in November.
Beyfortus is the first monoclonal antibody approved to protect all infants in the U.S. through their first RSV season. The drug is already approved in Europe, Canada and the United Kingdom.
The FDA previously approved another monoclonal antibody injection to protect some infants from RSV: a drug called Synagis. But it is approved only for high-risk infants and must be administered monthly during RSV season. The drug lowered the risk of hospitalization from RSV by 45% to 55% in trials.
In a study of nearly 1,500 infants, Beyfortus lowered the risk of developing a respiratory illness from RSV that required a doctor’s visit by nearly 75% for at least five months.
In a study of more than 1,400 infants born prematurely, which makes them more susceptible to severe illness, that figure dropped to 70%.
The most common side effects in the trials were rash and injection site reactions.
The FDA said Monday that Beyfortus comes with a warning about extreme immune responses such as anaphylaxis — severe or life-threatening allergic reactions — which have been observed with other monoclonal antibodies. The drug should also "be given with caution to infants and children with clinically significant bleeding disorders," the FDA said.
Another tool to protect infants from RSV may be available soon: An independent advisory committee to the FDA recommended Pfizer’s maternal RSV vaccine for pregnant mothers in May, but the FDA has not approved the shot yet. Two RSV vaccines for older adults, one from Pfizer and another from GSK, have received the agency's approval.
