Antibody response in school children to live rubella vaccine (Cendehill strain).

The efficacy of an attenuated rubella virus vaccine, Cendevax, was tested on 65 school children. Forty-nine of them (75%) had pre-existing antibodies and in these there was no increase in the HAI antibody titres after administration of the vaccine. Sixteen children (25%) had no demonstrable rubella HAI antibody prior to vaccination. From the latter group, postvaccination serum samples were available from only 11, and 10 of these seronegative children showed seroconversion after vaccination. The geometric mean HAI titre was 1:180. Seven of the 10 postvaccination serum samples had complement-fixing antibodies and specific IgM antibodies were detected by the immunofluorescence test in 8. No correlation was observed between the CF and the IgM antibodies.