Safety and Immunogenicity of a Novel Influenza Subunit Vaccine Produced in Mammalian Cell Culture

Abstract

Immunization remains the best prevention strategy for influenza, but production constraints for egg-based influenza vaccines have prompted the development of innovative cell culture manufacturing processes. Here, we describe a novel cell culture-derived influenza vaccine (CCIV) produced in Madin-Darby canine kidney cells. This phase 3, observer-blind, randomized, multicenter study in Poland compared the immunogenicity of a CCIV and a conventional egg-based vaccine. Participants, stratified by age (adults 18-60 years, n = 1300; elderly persons > or = 61 years, n = 1354), received a single intramuscular vaccination. Immunogenicity was assessed 21 days later by hemagglutination inhibition assay. Reactogenicity was assessed using self-completed diary cards. The immunogenicity of CCIV was noninferior to that of the conventional vaccine for all 3 vaccine strains in both age groups, regardless of underlying health status. Both vaccines fulfilled European Union registration criteria and were well tolerated, with similar incidences of solicited local and systemic reactions in both age groups; the only significant difference was an increased frequency of mild or moderate pain with CCIV than the conventional vaccine among adult (22% vs 17%; P < .05) and elderly (9% vs 5%; P < .001) vaccinees. CCIV was well tolerated and highly immunogenic in adults 18 years of age or older. Cell culture may offer greater flexibility of supply during periods of high demand for both seasonal and pandemic vaccines.