Standardization of techniques and reagents for the study of rubella antibody

The use of well-standardized assays or well-documented commercial kits for determination of rubella antibody titers is recommended. The expression of levels of antibody and the sensitivity of the assays in international antibody units should be encouraged; at present this is possible for IgG. The type of antibody assay and the antigen used must be defined. The standardization of IgM units is more problematic but is being developed. The degree of protection against viremia associated with low levels of antibody needs further elucidation.