Geneva, Switzerland – September 9, 2026
A four‑year evaluation of the maternal respiratory syncytial virus (RSV) vaccine RSVpreF (ABRYSVO®) has been prequalified by the World Health Organization (WHO) in a multi‑dose vial presentation. The new format is expected to lower costs and simplify delivery, especially for countries supported by Gavi, the Vaccine Alliance, and could protect millions of newborns from severe lower‑respiratory‑tract disease.
Why maternal vaccination matters now
RSV remains the leading cause of respiratory illness and pneumonia in infants worldwide. In low‑ and middle‑income countries (LMICs) where access to supportive care is limited, almost 97 % of RSV deaths occur. Maternal immunisation transfers protective antibodies across the placenta, shielding infants during the first six months of life—the period of greatest vulnerability.
Study scale and design
The prequalification builds on the single‑dose presentation that WHO approved in March 2025 and Gavi’s July 2025 decision to launch a maternal RSV vaccine programme. The multi‑dose vial was developed with support from the Gates Foundation and is manufactured to contain 120 µg of lyophilised RSVpreF antigen (60 µg each of RSV‑A and RSV‑B) reconstituted with sterile water to a 0.5 mL dose.
The vaccine is administered to pregnant women during the third trimester (from week 28 onward) to maximise trans‑placental antibody transfer. Clinical data from Phase III trials demonstrated robust immunogenicity and a safety profile comparable to other maternal vaccines.
"RSV is an incredibly infectious virus that infects people of all ages, but is especially harmful to infants, particularly those born premature, the population protected through maternal immunisation," says Dr Kate O’Brien, Director of Immunisation, Vaccines, and Biologicals at WHO.
Key findings from the prequalification dossier
- Efficacy: The maternal vaccine reduced RSV‑related hospitalisations in infants by 48 % in the first six months of life (95 % CI 38‑57 %).
- Safety: No serious adverse events were linked to the vaccine; the most common reactions were mild injection‑site pain and low‑grade fever.
- Cost‑effectiveness: Modeling by the WHO‑Gavi partnership estimates that the multi‑dose vial could lower the price per dose by up to 30 % compared with the single‑dose presentation, making it affordable for Gavi‑eligible countries.
Implications for global health policy
The WHO prequalification enables national immunisation programmes to procure the multi‑dose vial through existing vaccine procurement mechanisms. Countries can now plan large‑scale roll‑outs that integrate the maternal RSV vaccine into routine antenatal care, potentially averting tens of thousands of infant deaths each year.
Next steps and challenges
- Supply chain: Scaling up production to meet projected demand for > 10 million doses annually will require coordination with manufacturers and Gavi’s financing mechanisms.
- Implementation: Health ministries must train antenatal care providers, ensure cold‑chain capacity, and engage communities to address vaccine hesitancy.
- Monitoring: Post‑licensure surveillance will track real‑world effectiveness and safety, feeding back into WHO’s vaccine safety monitoring system.
Sources
- WHO news release, 9 September 2026 – “WHO prequalifies multi‑dose RSV vaccine vial, paving the way to protecting more infants globally.”
- WHO fact sheet, 30 May 2025 – Quote from Dr Kate O’Brien on RSV burden.
- Gates Foundation press release, 2024 – Funding for multi‑dose RSV vaccine development.
- Gavi investment strategy document, 2025 – Financing framework for maternal RSV vaccines.
FIRAT Editorial Board
Institutional Research Desk · Foresight Institute of Research and Translation
The collective editorial and research translation board of FIRAT, synthesising peer-reviewed evidence, policy briefs, and division milestones across our seven foundational research pillars.
