The postnatal acquisition of factors which affect the influenza haemagglutination-inhibition test.
Levels of maternally transferred antibodies against the surface antigen of the A/Texas/1/77 strain of influenza virus showed the expected decline during infancy when measured by complement fixation (CF). However, this decline was not observed when these antibodies were measured by haemagglutination-inhibition (HI). It has been postulated that this discrepancy is due to the acquisition, in the early days of life, of non-specific serum factors which increase the HI activity of sera. The levels of these factors were determined indirectly by calculating HI:CF ratios and it was shown that the factors are rapidly acquired by children between the fifth and twentieth week of life.
D000328:Adult; D000367:Age Factors; D000914:Antibodies, Viral / Q000032:analysis*; D000954:Antigens, Surface / Q000276:immunology; D002675:Child, Preschool; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007113:Immunity, Innate; D007112:Immunity, Maternally-Acquired; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology*
D000914:Antibodies, Viral; D000954:Antigens, Surface