Chapter 8. Cell Culture-based Influenza Vaccine Development

Abstract

Influenza vaccines are effective against many influenza A and B strain viruses, but suboptimal effectiveness has been observed against A/H3N2. Conventionally, the production of seasonal and pandemic influenza vaccines involves viral passage in chicken eggs. Haemagglutinin (HA) as the major vaccine antigen and virus surface protein needs to mutate in order to facilitate viral growth in eggs. These mutations may change the antigenicity of HA and thereby decrease vaccine effectiveness (VE). Cell culture technology offers advantages over egg-based methods. Cell-based vaccines are free of egg proteins, additives, and antibiotics. More importantly, the production of vaccine viruses in cells avoids the need for virus replication in eggs and egg-adaptive mutations, therefore viruses remain antigenically similar to wild-type strains. Antigenic characterisation performed by World Health Organization Collaborating Centres show that cell-derived A/H3N2 viruses match circulating strains more closely than egg-derived A/H3N2 viruses, and this is supported by additional studies. VE data also demonstrate that cell-derived vaccines are more effective than egg-derived vaccines in preventing influenza-like illness and influenza-associated hospitalisations in individuals of all ages, including those ≥65 years old, confirming the advantages of cell culture technology.