The European Community Guidelines 89/342 and 89/381 1 , define the procedures for production and control of influenza vaccines. These include tolerability and immunogenicity clinical studies to be conducted before marketing distribution. Three of these studies, carried out in Siena, Genoa and Chieti (Italy), are reported here. Six hundred and fourteen volunteers completed the study. Vaccines were randomly divided into four groups. Adults aged 18 to 60 years and elderly over 60 years old received either whole virus vaccine or subunit vaccine. All medical events were monitored for evidence of adverse reactions, especially during the first 7 days after immunization. Antibody assay was performed through single radial haemolysis (SRH). On the basis of our results we can conclude that: – the incidence of reactions was significantly lower in subjects over 60 years old than in subjects aged 18 to 60 for the whole virus vaccine; – subunit vaccine was well tolerated in both age groups and is significantly better tolerated than the whole virus one, in subjects aged 18 to 60, particularly for local reactions; – whole and subunit vaccines are both well tolerated by subjects over 60; – no significant differences were noted in the immunogenicity of subunit vaccine and whole virus vaccine except for H1N1 strain in the younger age group where the subunit vaccine was significantly more immunogenic; – the antibody response was significantly better in young adults (i.e., < 30 years of age)
