Rubella-specific serum and nasopharygeal immunoglobulin responses following naturally acquired and vaccine-induced infection. Prolonged persistence of virus-specific IgM.

Rubella-specific immunoglobulin responses in sera and nasopharyngeal secretions were compared in groups of adult females who had experienced naturally acquired rubella or infection induced by Cendehill, HPV77.DE-5, RA27/3 (subcutaneously and intranasally), and To-336 vaccines. Serum IgG and IgA and nasopharyngeal IgA responses after vaccination by RA27/3 intranasally most closely resembled those induced by naturally acquired infection. However, the other vaccines failed to induce a persistent local IgA response. Levels of local antibody induced by HPV77.DE-5 were especially poor. Virus-specific IgM was detected for prolonged periods. The highest levels and the most persistent response followed vaccination by HPV77.DE-5, four of five volunteers still having rubella-specific IgM at 1 year. Virus-specific IgM persisted for 6 months in seventeen of twenty-five (68%) and for a year in nine of twenty-four (38%) vaccinees. It was still present in four of nine (44%) naturally infected patients at a year.