WHO Recommends Maternal Vaccine and Monoclonal Antibody to Protect Infants from RSV

On May 30, 2025, the World Health Organization (WHO) issued a global recommendation for the use of both a maternal vaccine and a monoclonal antibody to protect infants against respiratory syncytial virus (RSV), a leading cause of acute lower respiratory infections in children worldwide.

RSV is responsible for approximately 100,000 deaths and over 3.6 million hospitalizations annually among children under five years of age, with about half of these deaths occurring in infants younger than six months. ^[1]. The majority of these fatalities (97%) take place in low- and middle-income countries, where access to supportive medical care is limited.

The WHO's recommendations, published in the Weekly Epidemiological Record, advocate for the administration of the maternal vaccine RSVpreF during the third trimester of pregnancy. This vaccine enables the transfer of protective antibodies from mother to fetus, offering the newborn passive immunity against RSV for approximately six months after birth.

In addition to maternal vaccination, the WHO recommends the use of the long-acting monoclonal antibody nirsevimab for infants. Administered as a single injection, nirsevimab provides immediate protection against RSV, lasting at least five months. It is particularly beneficial for infants under six months of age and can be given at birth, during the first health visit, or just before the RSV season, depending on the country's immunization strategy.

Both RSVpreF and nirsevimab received endorsement from the Strategic Advisory Group of Experts on Immunization (SAGE) in September 2024. Furthermore, the maternal vaccine was prequalified by the WHO in March 2025, facilitating its procurement by United Nations agencies.

Real-world data from Argentina presented at the European Society for Paediatric Infectious Diseases (ESPID) 2025 conference demonstrated a significant reduction in infant hospitalizations due to RSV following the implementation of maternal vaccination programs.^[2] These findings support the effectiveness of maternal RSV vaccination in reducing severe RSV disease in infants.

The WHO emphasizes that the greatest impact on severe RSV disease will be achieved by administering the monoclonal antibody to infants under six months of age. However, there is still a potential benefit among infants up to 12 months of age. The organization urges countries to consider these recommendations based on feasibility, cost-effectiveness, and anticipated coverage within their existing health systems.

References:

1. Li Y, et al. (2022). Global burden of respiratory syncytial virus-associated lower respiratory tract infections in older adults in 2020: a modelling study. The Lancet Infectious Diseases, 22(4), 473–485.

2. Mahmud, S., et al. (2025). Cost-Effectiveness of Bivalent Respiratory Syncytial Virus Prefusion F (RSVpreF) Vaccine During Pregnancy for Prevention of Respiratory Syncytial Virus Among Infants in Argentina. Infectious Diseases and Therapy.

(Input from various sources)

(Rehash/Sakshi Thakar/MSM)