Comparison of haemagglutination-inhibition and single-radial-haemolysis techniques for detection of antibodies to influenza B virus.

Some of the strains influenza B isolated between 1975 to 1978 showed a significant drift away from the prototype strain B/HK/8/73 when tested by cross haemagglutination-inhibition. A serum survey for antibody to two strains of influenza B virus was carried out comparing haemagglutination-inhibition (HI) and single-radical haemolysis (SRH) tests. The SRH technique was found to be more sensitive than the HI test.