A Parent’s Quiet Fear
It starts as a small cough. Then a wheeze. Then a long night watching your baby’s chest rise and fall a little too fast, wondering if this is the moment you need to rush to the emergency room.
For parents of newborns and infants, RSV, respiratory syncytial virus, is one of those fears that lives quietly in the back of the mind every fall and winter. It looks like a cold. It can become so much more. Since last fall alone, RSV has been responsible for over 51,000 pediatric hospital admissions in the United States, most of them children under 5 years old.
The good news is that science has been working hard to protect your baby before RSV ever arrives. And a new clinical trial just brought parents and pediatricians one step closer to understanding the safest, most effective way to do that.
What the New Research Found About RSV Combined Vaccines
A study published May 4, 2026, in the American Academy of Pediatrics looked at a question that many families and clinicians have been asking: What happens when a mother receives the RSV vaccine during pregnancy, and the baby also receives RSV immunization after birth? Is it safe? Does it work even better?
The answer, according to researchers, is reassuring on both counts.
The clinical trial followed 181 mother-infant pairs, divided into four groups to compare different combinations of maternal vaccination and infant immunization. The findings showed that neither mothers nor infants in any group experienced serious adverse events related to immunizations. Reactions in infants who received the monoclonal antibody nirsevimab were mild to moderate, about 17% had injection site pain, and about 60% experienced common systemic reactions like sleepiness or irritability, which resolved on their own.
Most importantly, all four groups showed significant increases in neutralizing antibody levels, the kind that help babies fight off RSV infection, and those levels remained high at three months of age.
As the study authors concluded, maternal RSV vaccination and infant immunization may be safely given together when the situation calls for it.
Understanding the Two Types of RSV Protection
There are currently two ways to protect a baby from RSV, and it helps to understand how they work together.
Maternal vaccination (RSVpreF): Given to the pregnant parent between 32 and 36 weeks of pregnancy, from September through January. The antibodies cross the placenta and give the baby immediate protection from birth. The benefit is that no injection is needed for the newborn. The limitation is that protection may wane more quickly over time.
Infant immunization (nirsevimab or clesrovimab): A single-dose monoclonal antibody given directly to the baby, ideally at birth or shortly after during RSV season. It produces antibodies that last longer and offers more flexibility in timing. The tradeoff is a higher cost and a small risk of the mild reactions described above.
For most families, one of these options is enough. The American Academy of Pediatrics (AAP) does not prefer one product over the other and recommends whichever licensed product is appropriate for the baby’s age and health status.
Who Needs RSV Immunization, and When
The AAP’s current policy makes clear recommendations about which infants should receive RSV immunization:
Babies under 8 months during their first RSV season, if any of the following apply:
- The pregnant parent did not receive the RSVpreF vaccine during pregnancy
- The pregnant parent’s vaccination status is unknown
- The baby was born fewer than 14 days after the pregnant parent was vaccinated
Children 8 through 19 months in their second RSV season, but only if they are considered high-risk, which includes:
- Children with chronic lung disease of prematurity who needed medical support in the six months before the second RSV season
- Children with severe immunocompromise
- Children with cystic fibrosis with severe lung disease or low weight-for-length
- American Indian or Alaska Native children, who face significantly higher rates of severe RSV disease and hospitalization, a disparity linked to social factors including access to running water, transportation, household crowding, and indoor air quality
Infants born during RSV season should ideally receive immunization within the first week of life, during their birth hospitalization when possible.
What This Means for Your Family
If you are pregnant or have recently given birth, here is the practical takeaway:
Talk to your OB or CT pediatrician about whether you received the RSVpreF vaccine during your pregnancy and when. That single piece of information determines whether your newborn needs additional immunization at birth.
If your baby is already here and you are unsure about their RSV protection status, bring it up at your next well-child visit. Immunization can be given at any healthcare visit, not only at birth.
And if your baby falls into a high-risk category, premature birth, lung disease, immunocompromise, or is American Indian or Alaska Native, make sure your provider knows, as the recommendations are different for the second RSV season as well.
RSV is not going away. But the tools to protect the most vulnerable infants have never been stronger, and the latest research confirms that using them together, when needed, is safe.
Have Questions? Speak With Our CT Pediatricians
Every baby’s situation is a little different. Whether you are weighing maternal vaccination, infant immunization, or wondering if your child qualifies as high-risk, contacting a CT pediatrician is the best person to help you navigate these decisions.
A short conversation at your next visit can give you the clarity and confidence to know your baby is protected.
This article is for informational purposes only and does not replace professional medical advice. If you have concerns about your baby’s health or RSV protection, please consult your healthcare provider.
Sources
Rostad, C. A., Healy, C. M., Nayak, J. L., Parameswaran, L., Creech, C. B., Martin, J. M., Brady, R. C., Jones-Beatty, K., Badell, M., Eppes, C., Quinn, M., Mulligan, M., Rolsma, S. L., Rick, A., Forde, B., Avadhanula, V., Piedra, P. A., Telu, K., Kunwar, P. S., … Campbell, J. D. (2026). Maternal RSV vaccination, infant nirsevimab, or both: Interim analysis of a randomized trial. Pediatrics, e2025075223. https://doi.org/10.1542/peds.2025-075223
American Academy of Pediatrics Committee on Infectious Diseases. (2025). Recommendations for the prevention of RSV disease in infants and children: Policy statement. Pediatrics, 156(5), e2025073923. https://doi.org/10.1542/peds.2025-073923
Jenco, M. (2026, May 5). Study: Maternal RSV vaccination combined with infant immunization is safe. AAP News. https://publications.aap.org/aapnews/news/35012/Study-Maternal-RSV-vaccination-combined-with