The mosquito-borne disease kills more than 600,000 people a year, mainly in Africa, according to the World Health Organization.
Children under five years old account for more than 80 percent of deaths on the continent.
Following a pilot phase, the RTS,S vaccine is being rolled out at scale across Africa, starting in Cameroon.
At a hospital in the town of Soa, 20 kilometres (12 miles) from the capital Yaounde, six-month-old Noah Ngah became the first to receive the injection at the facility.