Recombinant Bacille Calmette‐Guerin Expressing the Measles Virus Nucleoprotein Protects Infant Rhesus Macaques from Measles Virus Pneumonia

Measles virus infection continues to be a major cause of infant mortality. There is a need for a measles vaccine that can be administered at birth in the presence of maternal neutralizing antibody. Infant rhesus monkeys were immunized with recombinant bacille Calmette-Guérin expressing the full-length measles virus nucleoprotein (BCG-N) and subsequently challenged with measles virus. Nucleoprotein-specific lymphocyte proliferative responses were detected in the absence of anti-N antibody after vaccination. Vaccination with BCG-N did not prevent systemic measles virus infection; however, there was a significant reduction of lung inflammation after challenge. Virus titers in lymph nodes were significantly lower, and the duration of nasopharyngeal viral shedding was shorter in some vaccinated monkeys after challenge. These results suggest that measles virus-specific T cells were primed by BCG-N vaccination and that they prevented virus-induced lung pathology.