The international standard for anti-Brucella-abortus serum

In field trials on the eradication of brucellosis from dairy herds in Great Britain, which began in 1933, a serum standard of reference was used for the examination of agglutinating suspensions prepared in different laboratories. In 1937, the Office International des Epizooties (OIE) adopted this standard and made recommendations for its use internationally. These recommendations were revised by OIE in 1948, by the Third Inter-American Congress on Brucellosis and by the Joint FAO/WHO Expert Panel on Brucellosis in 1950, and again by the latter body in 1952. A new batch equivalent in potency to the original standard was established by the WHO Expert Committee on Biological Standardization in 1952 as the International Standard for Anti-Brucella abortus Serum.The International Standard, or a national standard of equivalent potency, ensures comparability of the titres obtained in different countries by different methods, and the results of such comparisons can be expressed in a simple manner by describing the titres in terms of International Units of Brucella antibody.