Influenza virus vaccine Begrivac ( CSL)

An automatable focus-reduction neutralisation test (AFRNT) for detecting influenza neutralising antibodies in serum was developed. The assay used immunoperoxidase staining and automated foci counting with AID Diagnostika ViruSpot software. Human serum samples (n=108) were collected before and after vaccination with Pandemrix or Begrivac and were tested by AFRNT and a haemagglutination inhibition assay (HI) using seasonal and pandemic influenza vaccine strains from 2009 to 2011. Much attention has been given to the factors that influence detection of neutralising titre, such as viral quantification and the use of receptor destroying enzyme (RDE) for serum treatment. Foci counting enabled precise virus quantification and the development of a highly sensitive assay. Pre-treatment of the human sera with RDE significantly reduced the neutralising titres against all strains, with the exception of the seasonal H1N1 (2009/2010) strain. An HI titre of 1:40, which is associated with a 50% clinical protection against influenza, was equivalent to an AFRNT titre of 1:100-1:200. In conclusion, the AFRNT is rapid, highly sensitive, and fully automatable; therefore, this test is perfectly suitable for the high-throughput detection of influenza-neutralising antibodies.

The aim of this study was to assess antibody response in 184 healthy adults vaccinated with split influenza vaccine (Begrivac, Chiron Behring). Response to hemagglutinin and neuraminidase was assessed before vaccination and after 1 month by hemagglutination inhibition test and neuraminidase inhibition test. After vaccination, statistically significant increases of antibody titers, both for hemagglutinins and for neuraminidases, were observed. The post-vaccination proportion of persons with protective antihemagglutinin antibody titers ranged from 78.4%to 90.8%, while the proportion of persons with at least a fourfold increase of antihemagglutinin antibody titers ranged from 50.5% to 71.2%. All requirements of the Committee for Proprietary Medicinal Products regarding humoral response to inactivated influenza vaccine in healthy adults were fulfilled. Due to a wide range of age of the persons included in this study, the results were also analyzed in two age groups: from 20 to 45 years and from 46 to 56 years. Nevertheless, there were no statistically significant differences in antibody response between these two groups either for hemagglutinin or for neuraminidase.