Pediatric intensive care specialist Job van Woensel explains: “We expect that this winter far fewer infants will be hospitalized with severe RSV infections. This antibody will prevent enormous suffering among babies and their parents.”

RSV is one of the leading causes of hospitalization among infants worldwide. In the Netherlands, thousands of babies are affected each year, with 150–200 ending up in pediatric intensive care. In countries where the new injection has already been introduced, hospital admissions have dropped by 80 percent, easing pressure on regular healthcare services as well.

Discovery in Amsterdam UMC
The scientific foundation for this breakthrough was laid in 2007, when immunologist Hergen Spits and his team developed a new method to keep immune cells alive outside the body. Using this technique, researchers Tim Beaumont and Etsuko Yasuda isolated a powerful antibody capable of neutralizing the RSV virus from the blood of a healthy adult donor.

From laboratory to nationwide protection
The further development of the RSV neutralizing antibody was initially carried out by Amsterdam UMC spin-off AIMM that later split off its infectious disease programs into Rsouth Antibodies. After an investment round from investors including Amsterdam UMC Ventures Holding, the antibody was licensed to AstraZeneca, where it was optimized and clinically developed into an effective medicine.

The result was nirsevimab, a long-acting version of the antibody that provides protection throughout the RSV season. Following successful clinical trials, the European Medicines Agency (EMA) granted approval in 2022, after which the European Commission and the Health Council of the Netherlands recommended including it in the Dutch National Immunization Program. In the 2024 spring budget (Voorjaarsnota), the Dutch government allocated funding to ensure that all babies could receive the protective treatment.

A global milestone for infants
As of September 2025, all Dutch babies born after March 31 are eligible for the protective injection. Beaumont reflects: “It’s incredibly rewarding to see a discovery from our lab now protecting babies worldwide. That’s what all the work was for.”

Read the scientific papers underlying this development on Nature Medicine and Science.