Meanwhile, Sanofi has pointed to Beyfortus’ 75% reduction in the incidence of MALRI versus Enflosia’s figure of 60%. The French company also has emphasized Beyfortus’ duration of protection through six months, which is now reflected on its new label in Europe.

Merck's shot will compete against a similar blockbuster treatment from Sanofi and AstraZeneca called Beyfortus.

Merck’s Enflonsia will go up against Sanofi and AstraZeneca’s Beyfortus, which the partners plan to ship out early in the third quarter.