The World Health Organization (WHO) has prequalified a version of the maternal vaccine against respiratory syncytial virus (RSV) that includes several doses in one vial.
Vaccinating pregnant people in the third trimester protects their newborns against RSV infection and reduces a baby’s risk of being hospitalized with the virus by more than 80%.
Vaccines need the WHO’s seal of approval before United Nations agencies such as UNICEF can buy them to distribute to lower-income countries.
Gavi, the Vaccine Alliance, agreed last year to fund the introduction of maternal RSV vaccination in multiple countries, and has been working to lay the groundwork for its rollout. Although the WHO prequalified single-dose vials in 2025, Gavi’s maternal RSV vaccination program could not begin until the agency prequalified multi-dose vials, which reduce the cost and difficulty of mass immunizations.
Benefits of multi-dose vials
Multi-dose vials allow healthcare professionals to vaccinate more people, but take up less storage space on delivery trucks or in clinics. Multi-dose products also make it easier to maintain a “cold chain,” in which vaccines are refrigerated at an appropriate temperature on the journey from the factory into people’s arms.
RSV hospitalizes 3.6 million and kills 100,000 children under age five years each year, according to the WHO. Newborns are especially vulnerable.
Pfizer released the maternal RSV vaccine, Abrysvo, in the United States in 2023. The Gates Foundation provided funding to develop a multi-dose version.
Getting the multi-dose product prequalified “is a key milestone for RSV and, more broadly, for pneumonia prevention and reducing infant mortality globally,” said Ignacio Esteban, Gavi’s senior policy manager and incoming head of the adult and adolescent vaccines portfolio.