Sanofi is shipping Beyfortus (nirsevimab) starting in early Q3 to ensure broad availability well ahead of the 2025-2026 respiratory syncytial virus (RSV) season, which typically starts in November and runs through March. Immunizations begin in early fall and these advance shipments provide confidence for healthcare providers to support their efforts. Demand has continued to increase since the launch of Beyfortus, the only option that can offer RSV protection designed for all infants with proven high, sustained efficacy through a typical RSV season and an unparalleled body of real-world evidence.

Sanofi, in collaboration with its partner AstraZeneca, has tripled production capacity and doubled the number of manufacturing sites since the launch of Beyfortus in 2023. Current supply for the upcoming season already matches the total doses distributed last year and production continues. Last season in the US, enough doses were produced to cover every infant — a benchmark that reflects both Sanofi’s and AstraZeneca’s global commitment to ensuring timely access for all infants.

Thomas Triomphe

Executive Vice President, Vaccines

“Our third year of providing RSV protection marks a transformative era in infant health. Backed by more than 40 real-world studies involving 250,000 immunized infants, Beyfortus has consistently proven itself as an effective RSV immunization. To meet growing demand since launch, we have meticulously primed our global distribution network to ensure Beyfortus will continue to deliver significant public health impact and offer high, sustained efficacy for infants regardless of underlying health conditions or the timing of when they are born.”

Beyfortus duration of protection extended through six months in the EU

This year’s EU shipments are marked by an important change to the Beyfortus EU label extending the duration of protection through six months, so Beyfortus can continue to offer season-long protection for all infants, including older babies immunized just before the RSV season begins. More than six million babies have been immunized worldwide and millions more will be immunized this season in more than 40 countries to help protect them from the potentially devastating impact of RSV disease.

All infants are at risk from RSV

RSV is a highly contagious virus infecting two out of three infants in their first year of life and nearly all children by their second birthday. RSV is the main cause of lower respiratory tract disease and a leading cause of hospitalization in all infants worldwide, with most hospitalizations occurring in healthy infants born at term.

With an extended half-life of 71 days, Beyfortus stands apart as the longest-acting monoclonal antibody for the prevention of RSV lower respiratory tract disease in infants, and the only RSV immunization designed to protect all infants born before or during the RSV season, at term or preterm, healthy or with underlying conditions. Administration can be timed to coincide with the RSV season and provided directly to newborns and infants as a single dose. Beyfortus offers rapid protection without requiring activation of the immune system. Beyfortus is also designed to protect children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season. Beyfortus was approved and granted special designations to expedite development across major geographies including the US, the EU, Japan and China.