Differentiation of Active and Passive Poliomyelitis Antibodies in Human Sera by Indirect Immunofluorescence

Summary The indirect method of immunofluorescence has been shown to detect antibodies for poliomyelitis virus. The reaction is specific for immunologic type and the FA titers correspond to the neutralizing antibody titers but are consistently lower. Paired sera from recovered cases and from vaccinated infants reflecting active antibody development show a marked increase in fluorescent antibody reaction. In contrast, most of the sera from infants containing high titers of passive antibodies which suppress active response to vaccine fail to stain by the indirect procedure of immunofluorescence. Possible explanations for this phenomenon are discussed.