Table 1 Comparative characteristics of selected seasonal influenza vaccinesa
Egg-based inactivated virus vaccine | Cell-based inactivated virus vaccine | Recombinant HA vaccine | |
|---|---|---|---|
Immunogen production | Influenza virions produced in eggs or cell cultures are purified, lysed with detergent to release hemagglutinin (HA) and neuraminidase (NA) oligomers, which form “rosettes” | Insect cells are lysed with detergent to release HA oligomers, which form “rosettes”. Does not contain NA | |
Required seeds | Candidate vaccine virus (CVV) “seed” must be produced – typically several weeks; possibly very few suitable CVV’s become available | Candidate vaccine virus (CVV) “seed” must be produced – typically several weeks; generally several suitable CVV’s become available | Recombinant vaccine virus “seed” must be produced – typically several weeks; do not need CVV, just HA sequence |
Mutation risk | Propagation of CVV in eggs selects mutations that decrease antigenic relatedness to native virus and may impact vaccine effectiveness | Production of CVV in mammalian cells minimizes risk of mutation and potential impact on vaccine effectiveness | Product made from stable (cell isolate) gene sequence, negligible mutation risk, but glycosylation may vary depending on host cells |
Immunogen yields | Variable depending on virus strain – often improved by further passaging or reassorting CVV (with increased risk of further mutations) | Variable depending on virus strain – may be improved by further passaging or reassorting CVV | Consistent productivity independent of virus strain, additional optimization of process possible |
Vaccine manufacture cost | Low – eggs are a relatively inexpensive production platform | Greater than egg-based – improvement may be possible with process optimization and larger production scale | |
Current US-licensed manufacturers | GSK Sanofi Pasteur Seqirus | Seqirus | Protein Sciences Corp. (now Sanofi Pasteur) |
Current share of US market | 85–90% | 10–15% | 1–2% |
