Nirsevimab and Maternal RSV Innoculation Shown to Be Safe, Effective in Conjunction

There are two medications available to prevent against respiratory syncytial virus (RSV) in infants: a vaccine given to pregnant mothers and a monoclonal antibody administered to infants prior to their first respiratory virus season. A Pediatrics study published in the June 2026 issue examines the safety of administering both the maternal RSV vaccine to pregnant mothers and providing nirsevimab to their infants and has found the method to be safe and effective at preventing RSV. These findings offer reassuring evidence in situations when both forms of protection are needed. The study, “Maternal RSV Vaccination, Infant Nirsevimab, or Both: Interim Analysis of a Randomized Trial,” (published online May 4) split 180 mothers and their 179 children into four groups: one with only the mother receiving the RSV vaccine; another where the mother was given the vaccine and the child nirsevimab at birth; a third where mothers received the vaccine and the child nirsevimab but three months post-birth; and a final group where only the newborns were given nirsevimab. Data showed across all groups that none of the mothers experienced any severe adverse events and infants experienced only mild to moderate side effects from the nirsevimab ranging from site pain and tenderness to fatigue and irritability. Mothers retained the antibodies from their vaccines beyond three months post-delivery but infants who were exposed only in the womb to the mother’s vaccine and did not receive nirsevimab saw their antibodies modestly wane by three months of life. Those infants who were exposed to the mother’s vaccine and received nirsevimab saw their antibodies increase and sustain through to their three-month examination. Authors state that while most infants won’t need both interventions, the administering of both can be done safely if parents and pediatricians choose to do so.

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The American Academy of Pediatrics is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists dedicated to the health, safety and well-being of infants, children, adolescents and young adults.