Comparison of haemagglutination-inhibition and single radial haemolysis techniques for detecting antibodies to influenza A and B viruses

The sensitivities of haemagglutination-inhibition (HI) and single radial haemolysis (SRH) techniques in detecting antibodies against influenza A/Bangkok/1/79, A/Brazil/11/78, B/Singapore/222/79, B/Hong Kong/5/72 strains, in human sera were compared. For antibodies to influenza B viruses the HI tests employing ether-treated antigens were also evaluated. The SRH technique appears to be more sensitive for detecting protective titres of antibodies against influenza B strains and influenza A/Brazil/11/78.