Immunogenicity and safety of quadrivalent versus trivalent inactivated influenza vaccine: a randomized, controlled trial in adults.

Background: Two phylogenetic lineages of influenza B virus coexist and circulate in the human population (B/Yamagata and B/Victoria) but only one B-strain is included in each seasonal vaccine. Mismatch regularly occurs between the recommended and circulating B-strain. Inclusion of both lineages in vaccines may offer better protection against influenza.

A phase III, randomized, open-label study to assess the tolerability and immunogenicity of an H5N1 influenza vaccine administered to healthy adults with a 1-, 2-, 3-, or 6-week interval between first and second doses.

Background: Preparedness for an H5N1 influenza pre-pandemic requires effective and well-tolerated emergency vaccination strategies that provide both pandemic strain-specific and heterologous protection.

Objectives: This was a pivotal study for the regulatory approval process for a candidate MF59-adjuvanted H5N1 vaccine. Its goals were to identify the preferred primary 2-dose vaccination schedule in adults and to assess whether the vaccine met European Committee for Medicinal Products for Human Use (CHMP) licensure criteria.