WHO prequalifies multi-dose RSV vaccine vial

The World Health Organization (WHO) has prequalified a multi-dose vial version of the maternal respiratory syncytial virus (RSV) vaccine, RSVpreF, also known as ABRYSVO

This prequalification could help more countries protect newborns and young infants from severe respiratory illness.

It is also expected to make maternal RSV vaccination more affordable and easier to deliver, particularly in low- and middle-income countries and countries supported by Gavi, the Vaccine Alliance.

The next step for maternal RSV vaccination

The latest WHO decision follows the prequalification of the vaccine’s single-dose presentation in March 2025. In July that year, Gavi announced plans to establish a maternal RSV vaccine programme to reduce the impact of the virus on newborns and young infants.

The multi-dose presentation is expected to improve the practicality of large-scale vaccination programmes by allowing health services to vaccinate more people from each vial. Its lower cost could also make it easier for countries to plan and introduce maternal RSV vaccination through national immunisation programmes.

The Gates Foundation supported the development of the presentation.

RSV continues to threaten young children

RSV is one of the leading causes of respiratory illness and hospitalisation among young children worldwide. Each year, the virus is estimated to cause more than 3.6 million hospitalisations and around 100,000 deaths among children under five.

Infants younger than six months are particularly vulnerable, accounting for almost half of these deaths. Around 97% of RSV deaths occur in low- and middle-income countries, where access to medical care and supportive treatment can be limited.

In some communities, seriously ill children may die at home before they can reach a health facility, highlighting the importance of preventing severe RSV infection before it occurs.

Protecting babies before they are born

The maternal RSV vaccine is designed to protect babies during their first six months of life. When a pregnant woman receives the vaccine, her immune system produces antibodies that can be transferred to the baby before birth.

WHO recommends that pregnant women receive RSVpreF during the third trimester, from 28 weeks of pregnancy onwards. The timing is intended to support the transfer of sufficient antibodies to the baby before birth.

Expanding global prevention

WHO recommends that countries introduce either the maternal RSV vaccine or the monoclonal antibody nirsevimab into their national programmes to help reduce severe RSV disease.

A lower-cost, multi-dose vaccine presentation is an important step toward expanding protection, particularly in countries with limited healthcare resources. By making vaccination programmes easier and more affordable to deliver, the new presentation could help protect more infants during the period when they are most vulnerable to severe RSV disease.