In early September, the American Academy of Pediatrics released new recommendations for the use of immunizations to protect infants from respiratory syncytial virus (RSV).^1,2 Additionally, the American College of Obstetricians and Gynecologists (ACOG) also made minor changes to their immunization schedule at the same time.³ These recommendations expanded on the information that we provided last year (available here).  This post aims to discuss the changes that have been made to the recommendations and why.

RSV activity in the United States and maternal immunization

The American College of Obstetricians and Gynecologists (ACOG) changed the recommended timing of maternal immunization vaccination in response to changes in RSV seasonality.³  The AAP technical report noted that RSV hospitalizations have also been peaking later, including in February during the 2025-2026 season.² The Centers for Disease Control and Prevention (CDC) defines RSV season when 3% of tests are positive.⁴ Looking at the seasonal data over the past few years, the season in most of the continental US has begun in October or November but continued through March or April.⁵ So it makes sense that ACOG with AAP reinforcement is recommending extending the months when maternal vaccination is recommended in the majority of the US now through March 1.^1-3  Infants whose mothers did not receive maternal RSV vaccination or received it less than 14 days before delivery are recommended to receive an RSV monoclonal antibody during the months of October through March.¹

Broadening of infants recommended to receive RSV monoclonal antibodies in season 2.

Another significant change the AAP recommends is to include a broader group of individuals in their second season RSV monoclonal antibody recommendations. This expansion was prompted in part by evidence noting that over 90% of those who were hospitalized in year 2 were not recommended to receive an RSV monoclonal antibody under previous recommendations.²  Their technical guidance nicely shares clear reasoning on what increased risks are associated with each of the additional indications.  These new season 2 indications include all infants born prior to 32 weeks gestation, all with hemodynamically significant congenital heart disease, all with anatomic pulmonary abnormalities or neuromuscular disorders, and those with Down syndrome or other chromosomal differences at higher risk of severe RSV disease.¹

Additional clinical considerations in the updated AAP recommendations for RSV prevention

The AAP’s update for RSV immunizations is very interesting as it opens the door to discussions that have been occurring in many hospitals.  For example, they continue to state that the monoclonal antibody should be administered within 1 week of discharge during the RSV season, but they add a qualification.  Specifically, they state that “providers may consider administering RSV immunization to eligible hospitalized infants during their hospitalization”.  Thus, this opens the door for this usage.  Importantly, they reinforce that data are limited for infants with a postmenstrual age of less than 32 weeks.^1,2

The other important consideration that I think is important to bring up is their reinforcement that antibody-depleting treatments (e.g., plasmapheresis, cardiopulmonary bypass, extracorporeal membrane oxygenation) can deplete/remove RSV antibodies. Consequently, the AAP reinforces the package insert information recommending redosing of a monoclonal antibody (or providing initial dosing, if they originally received protection via maternal vaccination) in these situations.¹

RSV immunization effectiveness in infants and young children.

The Vaccine Integrity Project conducted an updated systematic review of immunizations against seasonal viruses.  For RSV, the literature search was August 2024 through July 2025.⁶

In the RSV review they reported from a pooled analysis, maternal vaccination had 68% (95% CI 55-78) effectiveness at preventing infant hospitalization. In the analysis of adverse effects, no statistically significant increases in hypertensive disorders of pregnancy, stillbirth, placental abruption, or small for gestational age were noted.⁶

Nirsevimab effectiveness studies were also found for the first year of life.  In the many evaluations, nirsevimab consistently was reported to have between 79 to 84% effectiveness against medically attended infection, hospitalization, and critical care admission. ⁶

Summary of updated 2026 RSV immunizations to protect infants^1-3

• All infants younger than 8 months of age entering RSV season, should receive protection against severe RSV disease in year 1. Options include:
  • Maternal vaccination with Abrysvo between 32 weeks, 0 days and 35 weeks, 6 days gestation from September 1 through March 1 (generally sufficient if > 14 days prior to delivery; see AAP Policy for some exceptions) OR
  • Single dose of an RSV monoclonal antibody
    • Nirsevimab 50 mg for those < 5 kg or 100 mg for those ≥5 kg OR
    • Clesrovimab 105 mg
  • Select infants and children 8 through 19 months at high risk of severe RSV disease entering their second RSV season should receive RSV protection (regardless of if they had protection in year 1 or not). Groups that should receive monoclonal immunization with a nirsevimab 200 mg dose due to being at higher risk for severe RSV disease including those who were/have:
    • Born < 32 weeks gestation
    • Chronic lung disease attributable to prematurity or other neonatal conditions that require medical support at any time in the 6 months prior to the 2^nd season
    • Hemodynamically significant heart disease
    • Anatomic pulmonary abnormalities or neuromuscular disorders
    • Severe immunocompromise
    • Down syndrome or other chromosomal differences
    • Cystic fibrosis with severe lung disease or weight-for-length < 10^th percentile
    • American Indian or Alaska Native

Pharmacists’ role in protecting infants from severe RSV disease

Pharmacists who work in many areas can help protect infants from severe RSV disease.  First, those in community or ambulatory care may have opportunities to protect pregnant individuals.  Those who work in health systems can ensure all discharged newborns during indicated months receive the monoclonal antibody, if indicated.  Those who work in emergency departments and clinics can screen eligible infants who present for receipt of RSV immunization.

It is also important that those who work in pediatric hospitals, can have system level discussions regarding how, if at all, they may consider implementing pre-discharge administration for the highest risk individuals and how to educate providers about potential antibody depletion and the need for additional dosing, when appropriate.

By having many opportunities for screening, offering protection, and provider education, we can help to ensure that those families who want protection against severe RSV disease and hospitalization for their infants have access to it.

References

1. Committee on Infectious Diseases. Recommendations for the Prevention of RSV Disease in Infants and Children: Policy Statement. Pediatrics. 2026. doi:10.1542/peds.2026-079047
2. Committee on Infectious Diseases. Recommendations for the Prevention of RSV Disease in Infants and Children: Technical Report. Pediatrics. 2026. doi:10.1542/peds.2026-079049.
3. American College of Obstetricians and Gynecologists. 2026 Maternal Immunization Schedule. https://www.acog.org/clinical-information/maternal-immunization-schedule. Updated 2026. Accessed October 8, 2026
4. Centers for Disease Control and Prevention. Surveillance of RSV. https://www.cdc.gov/rsv/php/surveillance/index.html. Updated 2026. Accessed October 8, 2026
5. Centers for Disease Control and Prevention: US Department of Health and Human Services. National Respiratory and Enteric Virus Surveillance System (NREVSS) Interactive Dashboard. https://www.cdc.gov/nrevss/php/dashboard/index.html. Updated 2026. Accessed October 8, 2026
6. Scott J, Abers MS, Marwah HK, et al. Updated Evidence for Covid-19, RSV, and Influenza Vaccines for 2025-2026. N Engl J Med. 2025;393(22):2221–2242. doi:10.1056/NEJMsa2514268