Safety assessment and immunogenicity of a cell-culture-derived influenza vaccine in adults and elderly subjects over three successive influenza seasons.

Background: Adult and elderly subjects previously immunized with cell culture-derived (CCIV; Optaflu(®)) or egg-derived (TIV; Agrippal(®)) trivalent influenza vaccines were enrolled in two extension studies (E1 and E2) to evaluate safety and immunogenicity after revaccination with CCIV/TIV alone or in combination with concomitant pneumococcal vaccine (PV).

Methods: Adults and elderly subjects (n = 2609) were randomized 1:1 in E1 and allocated 3:1 in E2 to receive CCIV/TIV. In E2, a subset of elderly subjects was randomized to receive CCIV/TIV, with or without PV. Adverse reactions were monitored for six months and immunogenicity was assessed by hemagglutination inhibition (HI) assay using CHMP criteria.

Results: Overall, the safety profile of both vaccines was similar, no serious adverse events related to either vaccine occurred. Mild or moderate pain was the most commonly reported reaction. Reactogenicity was slightly higher in elderly subjects receiving CCIV/TIV concomitantly with PV [46% vs. 37%; p = non-significant (NS)]. Both vaccines met CHMP licensure criteria for adults and elderly subjects. With concomitant CCIV and PV, all three CHMP criteria were met for A/H1N1 and A/H3N2, whereas the B strain only met seroprotection and GMR criteria.

Conclusions: Safety and immunogenicity of CCIV was not influenced by the type of vaccine received previously or by concomitant PV administration.