FDA launches safety review of two RSV drugs for infants as RFK Jr. scrutinizes immunizations
The Food and Drug Administration has launched a safety review of two approved RSV drugs for infants, the latest immunizations to face scrutiny under Health Secretary Robert F. Kennedy Jr.
No safety issues have been reported with either of the respiratory syncytial virus drugs: Beyfortus, from Sanofi and AstraZeneca, and Enflonsia, from Merck.
Andrew Nixon, a spokesperson at the Department of Health and Human Services, said in an emailed statement that the FDA is “rigorously reviewing the available data, as it does for all products, to ensure decisions remain rooted in evidence-based science and in the best interest of patients.”
“FDA routinely evaluates emerging safety information and will update product labeling if warranted by the totality of the evidence,” Nixon said.
A Sanofi spokesperson said in an email that the safety and effectiveness of Beyfortus, a monoclonal antibody drug, has been demonstrated in over 50 clinical studies and real-world studies, involving more than 400,000 infants.
“At this time, no safety issue has been identified from clinical studies of nirsevimab or from post-marketing experience with more than six million babies immunized worldwide,” the spokesperson said, using the generic name of the drug.
A spokesperson for Merck said in an email that the bar for establishing the safety of vaccines and preventive therapies like Enflonsia “is exceptionally, and appropriately, high.”
“We met briefly with FDA representatives last week and we welcome ongoing scientific exchange and dialogue with the FDA and other regulatory or health authorities, their advisory committees, and scientific leaders on ENFLONSIA, including its safety profile,” the spokesperson said.
Reuters first reported that the FDA had launched a safety review.
Both drugs are monoclonal antibodies. They act similarly to vaccines, but instead of prompting the immune system to make antibodies, they deliver antibodies directly into the body in a process known as passive immunization.
The CDC recommends either product for infants under 8 months born during or entering their first RSV season. For older infants who are at increased risk, only Beyfortus is recommended. Both drugs are included in the CDC’s childhood immunization schedule.
It’s unclear whether the FDA will change the products’ labels or move to restrict their availability.
Dr. Sean O’Leary, a pediatric infectious disease expert and spokesman for the American Academy of Pediatrics, said he believes the review is meant to “sow distrust” in immunizations.
“I certainly hope nothing regulatory comes of this, because there’s no basis for it,” O’Leary said. “But even if it doesn’t, this systematic attempt to dismantle our immunization infrastructure is causing real harm in real time, in creating confusion among parents and even among clinicians.”
On Friday, a CDC vaccine advisory group handpicked by Kennedy voted to rollback a decadeslong recommendation that all newborns get a dose of the hepatitis B vaccine within 24 hours of birth. Major medical organizations decried the move.
O’Leary said rolling back access to RSV injections would “inevitably lead to fewer children receiving the monoclonal antibody and more kids getting hospitalized.”
Roughly two to three of every 100 infants under 6 months are hospitalized with RSV every year, according to the CDC. Most cases of RSV cause mild, cold-like symptoms, but it can also cause severe illness, including pneumonia and bronchiolitis, a lung infection that makes it difficult to breathe.
Cases of RSV are beginning to increase in parts of the U.S., according to the CDC.
“These products have been shown to be very safe in clinical trials,” O’Leary said. “Now that they’ve been put into broad use, we’re seeing really profound impacts on hospitalizations for young children.”
