VACCINATION WITH 2 DIFFERENT VACCINIA RECOMBINANT VIRUSES - LONG-TERMINHIBITION OF SECONDARY VACCINATION

the effects of immunity to vaccina virus on the efficiency of vaccinat ion with a vaccinia recombinant virus were studied. In mice the effici ency and duration of the B-cell response to the recombinant gene produ ct of a second vaccinia recombinant virus were suppressed for more tha n 9 months, i.e. practically lifelong. Antibody titres against the rec ombinant gene product were not only lower but also lasted for a shorte r time. Thus, immunity to vaccinia virus may influence both the titre and duration of the antibody response induced by a second distinct vac cinia recombinant vaccine.