South African medical scientists have launched a new study to evaluate the efficacy of Moderna’s vaccine as a booster shot against Covid-19. It will be rolled out to 15-thousand healthcare workers who have received their single Moderna dose or two doses of the J&J vaccine. eNCA speaks to Dr Nigel Garret is the Head of the Vaccine Programme at the Centre for the AIDS Programme of Research in South Africa. Courtesy #DStv403
