Each volunteer will be monitored for one hour (or longer if necessary) after each vaccination. Each volunteer will be visited at home daily for 6 days after each vaccination (Days 0, 28, and 56) by a field worker for assessment and recording of any solicited and unsolicited AEs in diary cards. If necessary the volunteer will continue to be seen regularly until any observed AEs have resolved or stabilised. Scheduled visits at the CNRFP will be on Days 0, 7, 28, 35, 56, 63, 84, and 140. All volunteers will be followed up to Day 140 post-first vaccination for adverse events.