Passively administered antibody suppresses the induction of measles virus antibodies by vaccinia-measles recombinant viruses.

We have used vaccinia-measles recombinant viruses to study vaccination in the presence of pre-existing antibody. When mice were vaccinated with recombinants expressing either the haemagglutinin (H) or fusion (F) measles virus (MV) proteins, the humoral response to the MV protein was suppressed by passively administered polyclonal antibody. However, individual monoclonal antibodies (H or F) did not affect the response. Mice whose anti-MV antibody response to H or F was initially suppressed by passive administration of anti-MV antibody were revaccinated 120 days later and gave a normal humoral response to the MV proteins. The VV-H recombinant induces a strong class I CTL response in Balb/c mice. This was not affected by the presence of levels of anti-MV antibody which inhibited the humoral response.