Flublok RIV or Fluzone IIV

Flublok RIV or Fluzone IIV refers to a trial-specific comparator arm consisting of two distinct, FDA-approved influenza vaccines manufactured by Sanofi. Flublok (Recombinant Influenza Vaccine, RIV) is an egg-free vaccine produced using recombinant DNA technology in an insect cell line (baculovirus expression system), specifically designed to provide a high dose of hemagglutinin (HA) antigens without the use of live influenza viruses or eggs. Fluzone (Inactivated Influenza Vaccine, IIV) is a traditional egg-based vaccine containing inactivated influenza virus (split-virion). Both vaccines are indicated for the prevention of seasonal influenza in adults and work by inducing an immune response against the viral hemagglutinin protein. In the context of clinical research, such as the Duke University Phase 4 study (NCT06518577), these vaccines serve as the standard-of-care active comparators to evaluate the immunogenicity and duration of antibody responses of newer cell-culture-based vaccines like Flucelvax.

Brand names

FlublokFluzoneFluzone Trivalent

Other names

RIVIIVRecombinant Influenza VaccineInactivated Influenza Vaccine