CSL Seqirus Publishes Phase 3 Results on Influenza Vaccine Combining Three Protection Approaches
CSL Seqirus announced the publication of pivotal Phase 3 study results for its MF59®-adjuvanted cell-based higher-dose quadrivalent influenza vaccine (aQIVc) in The Lancet Infectious Diseases. This marks a milestone as it is the first influenza vaccine to combine three proven approaches—MF59 adjuvant, cell-based manufacturing, and a high dose formulation—to enhance protection for older adults. The study involved 7,699 participants aged 50+ across eight countries and demonstrated superior immune responses compared to other enhanced vaccines. The trivalent version of the vaccine has already received regulatory approval in the UK and Europe for use in individuals over age 50. It showed non-inferiority versus a recombinant influenza vaccine, with strong safety results where most side effects were mild or moderate. The study also highlighted potential benefits from enhanced neuraminidase antibody responses, which could contribute to broader protection. CSL Seqirus is pursuing regulatory approvals in multiple markets and plans for phased introductions aligned with local policies. This development supports ongoing efforts by health authorities to improve influenza vaccination strategies for older adults.