Recombinant bacille Calmette-Guérin priming against measles.

Abstract

Live attenuated measles virus (MV) vaccines are ineffective in young infants because of neutralization by maternal antibody. An immunization strategy that may permit priming for T cell memory for MV in infants at or shortly after birth uses recombinant bacille Calmette-Guérin expressing the full-length MV nucleocapsid (N) protein (rBCG::N). C3H/He mice immunized with rBCG::N developed T cell responses and ELISA antibodies to the N protein and low levels of neutralizing antibody after intracranial infection with MV strain CAM/R40. There was considerable reduction in the virus titer recovered from brain homogenates, a decrease in the incidence and severity of histologic encephalitis, and a decrease in mortality in rBCG::N-printed C3H/He mice compared with control mice. Given the limitations of existing live attenuated MV vaccines, these results encourage the further testing of rBCG::N vaccines in primate models.