Increased immunogenicity of the MF59-adjuvanted influenza vaccine comparedto a conventional subunit vaccine in elderly subjects

Three-hundred and eight outpatient elderly subjects (greater than or equal to 65 years) were randomly assigned to receive the MF59-adjuvanted influenz a vaccine (FLUAD; n = 204) or a conventional subunit influenza vaccine (AGR IPPAL S1; n = 104) in order to compare the safety and immunogenicity of the two vaccines. Although mild pain at the injection site was reported more f requently by subjects immunised with the adjuvanted vaccine, both vaccines were shown to be safe and well tolerated. The adjuvanted vaccine was more i mmunogenic as indicated by higher post-immunisation geometric mean titres ( GMTs) and by higher proportions of subjects with post-immunisation greater than or equal to four fold increases of antibody titres or subjects with gr eater than or equal to 1/160 post-immunisation HI titres. These differences , statistically significant for all three strains after immunisation, indic ated that, by addition of the MF59 adjuvant emulsion, conventional subunit influenza antigens acquire an enhanced immunogenicity without any clinicall y significant increase of their reactogenicity.