The World Health Organization (WHO) has prequalified the multi-dose vial presentation of RSVpreF (Abrysvo), a maternal Respiratory Syncytial Virus (RSV) vaccine, in a move expected to support wider access to vaccination against severe RSV disease among infants.

The prequalification follows WHO’s approval of the vaccine’s single-dose presentation in March 2025 and Gavi, the Vaccine Alliance’s decision in July 2025 to establish a maternal RSV vaccine programme. The multi-dose presentation is expected to make the vaccine more affordable and facilitate large-scale vaccination programmes, particularly in countries supported by Gavi.

RSV is estimated to cause more than 3.6 million hospitalisations and around 100,000 deaths among children under five each year. Nearly half of these deaths occur among infants younger than six months, while about 97 percent of RSV deaths occur in low- and middle-income countries.

The maternal vaccine is designed to protect infants during their first six months of life through the transfer of antibodies from the mother to the baby before birth. WHO recommends that countries introduce either the maternal RSV vaccine, RSVpreF, or the monoclonal antibody nirsevimab into their national immunisation programmes.

WHO recommends administering RSVpreF to pregnant women during the third trimester, from 28 weeks of pregnancy onwards, to support antibody transfer to the infant.