Quadrivalent Recombinant Influenza Vaccine Found Superior to Egg-based Flu Shots

A recent study published by The New England Journal of Medicine confirmed the benefits of getting a quadrivalent recombinant influenza vaccine this flu season.

Although numerous clinical studies have shown that high-dose influenza vaccines (Flublok®) offer benefits over egg-based flu shots, “Data are needed on the relative effectiveness of recombinant vaccines as compared with standard-dose vaccines against influenza-related outcomes in adults under the age of 65 years,” wrote these researchers on December 14, 2023.

The Sanofi-funded study population included 1,630,328 vaccinees between 18 and 64 years old.

During this study period, 1,386 cases of PCR-confirmed influenza were diagnosed in the recombinant-vaccine group and 2,435 cases in the standard-dose group.

Among the participants who were 50 to 64 years of age, 2.00 cases per 1000 tested positive for influenza in the recombinant-vaccine group compared to 2.34 cases per 1000 in the standard-dose group.

This data indicates a relative vaccine effectiveness of 15.3%; 95% confidence interval [CI], 5.9 to 23.8; P=0.002).

However, the recombinant vaccine was not significantly more protective against influenza-related hospitalization than were the standard-dose vaccines.

In summary, the high-dose recombinant vaccine conferred more protection against PCR-confirmed influenza than an egg-based standard-dose vaccine among adults between 50 and 64 years old.

Flublok is made by Sanofi and is licensed by the U.S. Food and Drug Administration and the European Medicines Agency as Supemtek.