Sanofi, AZ's Beyfortus already in short supply as RSV season prompts surge in demand

Just a few months after Sanofi and AstraZeneca scored a key FDA nod for their respiratory syncytial virus (RSV) antibody Beyfortus, the long-awaited prophylactic is already in short supply.

In an advisory issued by the Centers for Disease Control and Prevention (CDC), the agency recommends doctors prioritize available Beyfortus 100-mg doses for infants at the highest risk of severe RSV disease. This includes infants younger than six months of age and those with underlying health conditions.

Sanofi is working with the CDC to maintain equitable distribution and attributed the supply strain to “higher than anticipated demand,” the company said in a statement. The shortage comes despite an “aggressive supply plan built to outperform past pediatric vaccine launches,” Sanofi added.

“We are working with our alliance partner in charge of manufacturing, AstraZeneca, to accelerate additional supply and explore a number of actions to extend the manufacturing network,” Sanofi's statement said.

Beyfortus won FDA approval in July as a passive immunization for RSV-related lower respiratory tract disease in newborns and infants born during or entering their first RSV season, plus young kids up to 24 months old who remain at risk from the virus through their second season.

In June, Sanofi’s global RSV franchise head Kimberly Tutwiler said on a conference call that Beyfortus manufacturing was already underway for the U.S. and that the company expected to “fulfill the demand for the coming season.”

As the first option of its kind, demand for Beyfortus was expected to be high even before the med officially scored approval. On the June call, Tutwiler pointed out that Sanofi was engaging with many physicians and public health experts who’ve been “waiting for decades for a solution for RSV that they could offer to the broad infant population.”

As the RSV season starts up, Pfizer’s Abrysvo represents another prophylactic option. The shot is recommended for people who are between 32 and 36 weeks pregnant to protect infants against RSV-associated lower respiratory tract disease through the first six months of life.

Pfizer's Abrysvo nabbed approval shortly after Sanofi and AstraZeneca’s green light.