Antibodies to measles virus surface polypeptides in an immunized student population before and after booster vaccination.

Serum specimens collected from 82 students before and after booster immunization with live measles virus (MV) vaccine were tested for MV surface protein-specific antibodies using a previously developed competitive enzyme immunoassay (EIA). The specificity of the assay in measuring antibodies against three sites on the haemagglutinin (H) and two on the fusion (F) protein was demonstrated. All subjects in this study were vaccinated, as one to two year-olds, three times with inactivated killed vaccine and later once or more with live vaccine. Fifty-three students were administered only live measles virus vaccine (M), whereas 29 were vaccinated with the MV combined with mumps and rubella (MMR). There was a clear tendency to a lower increase in antibody titres when MMR vaccine was used. This difference between the groups was most pronounced in antibodies against the site defined by a monoclonal antibody (mAb) I29. Antibodies to the site defined by the mAb 16AG5 on the F protein had no correlation with any of the other tests which suggests that subjects originally vaccinated with killed vaccine may have developed a distinct response to this site.