• New real-world evidence shows Beyfortus (nirsevimab) substantially reduced RSV lower respiratory tract disease and hospitalizations in infants during the 2023-2024 RSV season, versus no intervention^1-6
• Results add to the consistent high efficacy of Beyfortus against medically attended RSV lower respiratory tract disease, shown in the pivotal clinical studies and the outcomes from HARMONIE, a phase 3b clinical study conducted in close to real-life conditions^7-10

Beyfortus reduced respiratory syncytial virus (RSV) hospitalizations by 82% (95% CI: 65.6 to 90.2) in infants under 6 months of age, compared to infants who received no RSV intervention, according to the interim results of an ongoing study published in The Lancet. These results, from the first RSV season after Beyfortus’ introduction, are part of the three-year NIRSE-GAL study conducted in Galicia, Spain under a collaborative framework with the Galician Directorate of Public Health of the Xunta de Galicia (Galician government) and Sanofi.¹

The results echo real-world evidence (RWE) reported from several broad infant immunization programs across the US, Spain and France during the 2023-2024 RSV season, which add to the consistent and high efficacy seen in pivotal clinical studies with Beyfortus. Real-world evidence demonstrates if a treatment or immunization is effective in day-to-day practice, as opposed to “efficacy” determined in carefully controlled clinical trials. A favorable safety profile was observed following Beyfortus use, consistent with clinical study results.^1-10

Federico Martinon Torres
Head of Pediatrics, Hospital Clínico Universitario Santiago, Spain and principal investigator of NIRSE-GAL study
“Galicia provides the first population-based real-world evidence of the impact of nirsevimab to prevent RSV disease in infants, showing a reduction by almost 90% in the number of hospitalizations due to this virus when compared with several previous RSV seasons. This achievement is the result of the exemplary pragmatic collaboration among scientists, industry, healthcare providers and policy makers aligned with a carefully planned roll-out of the immunization campaign, and the outstanding response of the Galician parents to this prophylaxis campaign.”

Thomas Triomphe
Executive Vice President, Vaccines, Sanofi
“The scale and speed of impact seen after Beyfortus’ introduction demonstrates the strength of all-infant immunization strategies against RSV in babies. In Galicia, we saw an effectiveness of 82% in reducing RSV hospitalizations following the launch of Beyfortus, with more than 90% of eligible infants immunized. A growing body of evidence from these programs support policymakers, healthcare providers and parents who share our collective ambition to safeguard babies from RSV disease.”

NIRSE-GAL is a large, population-based, three-year follow-up study to evaluate the effectiveness of Beyfortus following its inclusion in the Galician immunization schedule. The study aims to measure the impact of Beyfortus on hospitalizations due to RSV, all-cause lower respiratory tract disease, severe lower respiratory tract disease caused by RSV, all-cause lower respiratory tract disease hospitalizations, and all-cause hospitalizations among infants born during the RSV season, infants under 6 months of age at the start of the season, and children aged 6-24 months who are vulnerable to severe RSV disease at the start of the season. The 2023-2024 immunization campaign ran from September 25, 2023 to March 31, 2024.¹

RWE from countries with Beyfortus all-infant immunization programs in 2023-24

In addition to this new effectiveness study, evidence of the high impact following Beyfortus’ introduction has been consistently shown in several other real-world studies.

• An interim analysis of 2023-24 surveillance data published in the US Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report (MMWR) shows a single dose of Beyfortus was 90% effective in preventing hospitalizations due to RSV in babies who were immunized below 8 months of age.²
   
• A recent draft recommendation from Haute Autorité de Santé in France reported, across six hospitals, an effectiveness of 83% against RSV-associated hospitalization in infants who received Beyfortus compared to those with no intervention.³  
   
• In Catalonia, Spain, a study pre-printed in The Lancet showed reductions of 87.6% and 90.1% in hospital and ICU admissions for RSV, respectively, among babies born before the start of the RSV season, who were eligible to receive Beyfortus, compared to those with no intervention.⁴
   
• A pooled analysis of data from three Spanish regions, including Valencia, Murcia, and Valladolid, showed an 84.4% effectiveness in preventing hospitalizations due to RSV in infants under 9 months of age versus infants who received no intervention. The results were published in Eurosurveillance.⁵
   
• A study from Navarra, Spain published in Vaccines found an effectiveness of 88.7% in preventing hospitalizations among infants immunized at birth with Beyfortus, compared to no intervention.⁶
   

The expansion of the Beyfortus manufacturing network is progressing well and according to plan. This expansion will allow Sanofi and AstraZeneca to more than triple manufacturing capacity. Based on this, and assuming regulatory validations are delivered in due time by regulatory agencies, Sanofi and AstraZeneca are confident to meet global commitments and build inventory that can be used in future RSV seasons. In addition, the companies are producing Beyfortus well in advance of the RSV season, with the vast majority of doses planned to be available by October.