Correlates of Protection for Influenza VaccinesAuthor: Claudia Maria Trombetta
The immunogenicity of a vaccine is estimated in terms of its capacity to induce an antibody and/or cell-mediated immune response in recipients. Studies have shown that antibodies against viral haemagglutinin are important correlates of protection. Traditionally, the assessment of immunogenicity is based on two serological assays, the haemagglutination inhibition assay and single radial haemolysis. A haemagglutination inhibition titer of 40 is considered to be an immunological correlate of protection and is regarded as the best available parameter of protection against infection.