WHO Backs Multi-Dose RSV Vaccine to Protect Infants
核心洞察
WHO granted prequalification to a three-dose vial presentation of Pfizer's maternal RSV vaccine Abrysvo, enabling large-scale distribution in lower-income countries.
RSV is the second leading cause of infant mortality globally after malaria, with over 100,000 deaths annually in children under five and more than 97% in low- and middle-income countries.
Pivotal Phase 3 trials showed 81.8% efficacy against severe RSV-associated lower respiratory disease in infants' first 90 days, sustained at 69.4% through six months.
The World Health Organization granted prequalification on Wednesday to a three-dose vial presentation of Pfizer's maternal respiratory syncytial virus (搜索) vaccine, marketed as Abrysvo. The decision allows global health alliances to introduce affordable immunisation during pregnancy in lower-income countries, where pregnant women vaccinated in the third trimester transfer protective antibodies across the placenta and shield infants through their first six months of life.
WHO data cited in the announcement place RSV as the second leading cause of infant mortality globally after malaria, with more than 100,000 deaths annually among children under five. Over 97% of those deaths occur in low- and middle-income countries, with a particularly high burden in sub-Saharan Africa, where facilities often lack specialised respiratory care. According to the European Medicines Agency (搜索), the vaccine showed high efficacy across high- and low-income settings: 81.8% against severe RSV-associated lower respiratory disease in the infant's first 90 days in pivotal Phase 3 trials, maintaining 69.4% efficacy through six months.
Gavi, the Vaccine Alliance (搜索), welcomed the decision and said it would expand access for lower-income countries. Building on its board approval of a dedicated maternal programme for the 2026-2030 strategic period, Gavi said eligible low-income countries can now apply for funding to integrate maternal immunisation into routine healthcare. The vaccine was developed with support from the Gates Foundation (搜索) and packs multiple doses per vial, reducing cold-chain and logistical costs. Post-authorisation surveillance in the United States found no statistically significant increase in preterm birth rates among vaccinated mothers, and post-marketing programmes in Europe and the United States continue to track real-world outcomes.