Key Points

While the maternal vaccine -- RSVpreF -- can be given to pregnant women in their third trimester to protect their infant, the long-acting monoclonal antibody -- nirsevimab -- can be administered to infants from birth, just before or during the RSV season, stated the recommendations, published in the Weekly Epidemiological Record (WER).

“Every year, RSV causes about 100,000 deaths and over 3.6 million hospitalisations in children under the age of 5 years worldwide. About half of these deaths occur in infants younger than 6 months of age,” the WHO said.

"The vast majority (97 per cent) of RSV deaths in infants occur in low- and middle-income countries where there is limited access to supportive medical care, such as oxygen or hydration," it added.

Although RSV causes mild symptoms similar to the common cold, including runny nose, cough, and fever, it can lead to serious complications. This can include pneumonia and bronchiolitis -– in infants, young children, older adults, and those with compromised immune systems or underlying health conditions.

Both RSVpreF and nirsevimab were recommended by the Strategic Advisory Group of Experts on Immunisation (SAGE) for global implementation in September 2024. In addition, the maternal vaccine received WHO prequalification in March 2025, allowing it to be purchased by UN agencies.

While the vaccine can be given during routine antenatal care, nirsevimab is given as a single injection of monoclonal antibodies that starts protecting babies against RSV within a week of administration. It lasts for at least 5 months and can cover the entire RSV season in countries with RSV seasonality.

The global health body recommends that infants receive a single dose of nirsevimab right after birth or before being discharged from a birthing facility. If not administered at birth, the monoclonal antibody can be given during the baby's first health visit.

If a country decides to administer the product only during the RSV season rather than year-round, a single dose can also be given to older infants just before entering their first RSV season, the WHO said.

The greatest impact on severe RSV disease will be achieved by administering the monoclonal antibody to infants under 6 months of age. However, there is still a potential benefit among infants up to 12 months of age, it added.

“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 Immunisation, Vaccines, and Biologicals at WHO.

“The WHO-recommended RSV immunisation products can transform the fight against severe RSV disease, dramatically reduce hospitalisations, and deaths, ultimately saving many infants lives globally,” O’Brien added.

- IANS