Murine cytomegalovirus inactivated by sodium periodate is innocuous and immunogenic in mice and protects them against death and infection.

Sodium periodate (10 mM, 4 degrees C) inactivated murine cytomegalovirus (MCMV) very rapidly (loss of 2 to 3 log of viral infectivity per minute). Periodate-treated MCMV (PI-MCMV) was shown to be innocuous in mice, as determined by the inability of the virus to replicate. PI-MCMV induced a strong humoral immune response, with a high level of neutralizing antibodies. Mice immunized with PI-MCMV were protected against death and infection, when a lethal challenge with the virulent virus was administered 3 weeks after immunization and from death but not infection when virulent virus was administered at 3 months. Finally, no reactivation of potentially latent challenge virus (sublethal dose at 3 weeks) was observed in animals immunosuppressed at 6 months after immunization. Taken together, these results suggest that periodate could serve as an inactivating agent to prepare killed vaccines.