WHO Recommends RSV Protection for Infants and Pregnant Women

The World Health Organization (WHO) has issued its first official recommendations on immunization products designed to protect infants against respiratory syncytial virus (RSV), the leading cause of acute lower respiratory infections in young children.

RSV is responsible for approximately 100,000 deaths and more than 3.6 million hospitalizations annually in children under five, with nearly half of these deaths occurring in infants younger than six months.

The vast majority—about 97 percent—of RSV-related infant deaths occur in low- and middle-income countries due to limited access to life-saving care like oxygen therapy and hydration.

WHO’s new position paper, published in the Weekly Epidemiological Record, outlines guidance for two products: a maternal vaccine for pregnant women and a long-acting monoclonal antibody for infants.

“RSV is an incredibly infectious virus that infects people of all ages, but is especially harmful to infants, particularly those born premature, when they are most vulnerable to severe disease,” said Dr. Kate O’Brien, Director of Immunization, Vaccines, and Biologicals at WHO.

“The WHO-recommended RSV immunization products can transform the fight against severe RSV disease, dramatically reduce hospitalizations, and deaths, ultimately saving many infant lives globally,” she added.

The maternal vaccine, RSVpreF, is recommended during the third trimester of pregnancy—beginning at week 28—to maximize antibody transfer from mother to baby.

This vaccine can be administered during routine antenatal checkups and was prequalified by WHO in March 2025, enabling its purchase through United Nations procurement systems.

The second product, nirsevimab, is a monoclonal antibody given to newborns as a single injection that provides protection lasting at least five months, covering the full RSV season in seasonal countries.

WHO recommends that nirsevimab be administered immediately after birth or at the first health visit, and in countries with seasonal RSV outbreaks, just before an infant enters their first RSV season.

Although the highest impact is seen in infants under six months, benefits may extend to those up to 12 months of age.

These recommendations were initially endorsed by WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) in September 2024.

RSV typically causes cold-like symptoms such as runny nose, cough, and fever, but in vulnerable populations it can lead to serious complications including pneumonia and bronchiolitis.

The WHO guidance highlights that countries should choose which product to implement—RSVpreF or nirsevimab—based on healthcare system readiness, affordability, and potential coverage rates.

The global health body emphasized that the new position paper is intended to support national policymakers, immunization program managers, and funding agencies in planning RSV prevention strategies.

With the inclusion of RSV immunization in national programs, WHO believes a significant reduction in infant mortality and morbidity is possible, especially in resource-constrained settings.