Antigenic Analysis of Influenza Viruses by Complement Fixation

[摘要] The data presented indicate that the complement fixation test with homologous strain-specific viral (V) antigen is suitable for the evaluation of antibody responses following immunization with monovalent influenza A2 virus vaccines. The results obtained are compatible with those reported by others who used the hemagglutinationinhibition techniques for assay.In two of the groups under study the incidence of specific anti-A2V responses was low after one or two intradermal injections of 20 CCA units of virus (18 and 60%), higher after one (63–73%) and best after two subcutaneous doses of 200 CCA units (τ;90%). When the first injection induced a specific antibody response, a second dose given within 2–4 weeks often failed to increase the titers, although negative reactors were thereby often converted to positive.There was evidence that the incidence and height of anti-A2V responses following the first dose increased to some extent with advancing age of the vaccinees, but a second dose, as a rule, eradicated these differences.A certain percentage of the subjects in all age groups who were given vaccine subcutaneously possessed measurable anti-A2V in their sera prior to immunization and prior to the dissemination of A2 virus. Their anti-A2V responses were higher than responses seen in persons lacking anti-A2V in the base line serum.In the third study group, which had experienced an A1 influenza outbreak 8 months earlier, with the development in over 30% of the patients of anti-A2V along with antibodies to the infecting strain, even a single intradermal dose of 20 CCA units of A2 influenza vaccine yielded good anti-A2V levels in over 80% of the individuals. This unusually high incidence of responses to the small dose of vaccine was not restricted to those persons who had been overtly ill previously or had formed anti-A2V at that time. It is suggested, therefore, that a clinical or inapparent infection in the recent past with an apparently unrelated influenza A strain might have supplied a conditioning stimulus which resulted in the heightened responses to the A2 virus vaccine.The implications of these findings have been discussed.

[学科分类] 生物科学（综合）