The race to protect infants from Respiratory Syncytial Virus (RSV) is gaining momentum, with a pivotal moment in 2025. The World Health Organization (WHO) has prequalified a maternal RSV vaccine, Abrysvo®, developed by Pfizer, Inc., marking a significant step towards global prevention. This vaccine, recommended by both WHO and the Pan American Health Organization (PAHO), is a game-changer for low- and middle-income countries (LMICs).
But here's where it gets controversial: While the single-dose vial of the maternal vaccine is a breakthrough, the focus now shifts to a multi-dose vial presentation, better suited for LMICs. This could be available as early as 2026, addressing price and supply barriers for many LMICs. However, some argue that long-acting monoclonal antibodies, also WHO-recommended, might be a more accessible option for now, despite their current limitations.
The maternal vaccine is a powerful tool in the fight against RSV, which is the leading cause of severe respiratory infections and hospitalizations in infants and young children. Nearly all children contract the virus before their second birthday, with stark disparities in mortality rates between low- and high-income settings. The vaccine, administered during pregnancy, enhances a pregnant woman's immunity and increases natural antibody transfer to the baby, providing vital protection during their most vulnerable months.
Pfizer's maternal vaccine has shown impressive results in clinical trials, with high protection levels through 6 months after birth. Real-world data from countries like Argentina further validate its effectiveness, especially against severe disease. Introducing these vaccines could not only reduce hospitalizations but also alleviate healthcare costs and strain on families and health systems.
Expanding access to maternal vaccines is crucial. WHO's recommendations build on a strong track record of maternal immunization for diseases like tetanus, influenza, and pertussis. Maternal vaccines offer distinct advantages, providing protection for both mother and child, and helping infants when they're too young for certain vaccines. PATH's research in Africa aims to understand adoption readiness and delivery requirements, ensuring these vaccines are well-positioned for success.
However, the journey to widespread adoption is not without challenges. Countries must consider the local impact of RSV, the cost and benefits of available products, and their integration into health systems. Prioritizing planning for vaccine rollout, raising awareness among healthcare providers, and ensuring workforce readiness and funding are essential steps. With the right preparation, maternal RSV vaccines can become a smart investment in maternal and child health, saving lives and easing the burden on vulnerable communities.
