Meningococcal serogroup A and tetanus immunity two years after MenAfriVac™ introduction in Mali

ents. Symptomsof gastroenteritis, includingvomitinganddiarrhea, occurring in the in-patient unit were recorded post-challenge. Results: In the per protocol population, 4/48 (8.3%) of placebo subjects and0/50 (0%)of vaccine subjects experienced severevomiting (100% reduction, p =0.054). 8/48 placebo subjects (16.7%) vs. 1 vaccine subject (2.0%) experienced moderate or severe vomiting (88.0% reduction, p =0.015), and 17/50 placebo subjects (35.4%) vs. 4/48 vaccine subjects (8.0%) experienced mild, moderate or severe vomiting (77.4% reduction, p =0.001). Reports of vomiting or diarrhea of any severity were significantly reduced in the vaccine group (10/50, 20%) compared with the placebo group (20/48, 41.7%; p=0.028), a 52% reduction. Conclusion: In this study the experimental norovirus vaccine was associated with significant reductions in vomiting. This bivalent norovirus vaccinemayprovide ameans to reduce transmission via aerosolized virus and contaminated fomites as a result of a reduction in vomiting episodes. Field efficacy studies arewarranted to further evaluate protection.