title: Antibody responses after repeated influenza A virus immunizations among schoolchildren in Japan.
abstract: Antibody responses to influenza virus immunizations were examined among junior high school students. The students received two doses of a commercial split-product vaccine containing influenza A H1N1 during a 2-year period following the first appearance of H1N1 virus in the winter of 1977-78. In haemagglutination-inhibition (HI) tests, the students who had been infected with H1N1 virus in 1977-78 showed a better response and wider cross-reactivity to the drift strain than the students who had not experienced earlier H1N1 influenza infection. Neuraminidase-inhibition (NAI) antibody titres after immunization depended upon a history of natural infection with H1N1 virus, since students not previously infected showed no significant NAI antibody rise after immunization.
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000032:analysis*; D003429:Cross Reactions; D006389:Hemagglutinins, Viral / Q000276:immunology; D006801:Humans; D009980:Influenza A virus / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control; D007564:Japan; D009439:Neuraminidase / Q000276:immunology; D009698:Nucleoproteins / Q000276:immunology; D014611:Vaccination; D014764:Viral Proteins / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D006389:Hemagglutinins, Viral; D009698:Nucleoproteins; D014764:Viral Proteins; D009439:Neuraminidase