A large-scale trial of what has been called the world’s first malaria vaccine to give partial protection to children is due to start in Malawi.
The RTS,S vaccine trains the immune system to attack the malaria parasite, which is spread by mosquito bites.
Earlier, smaller trials showed that nearly 40% of the 5-to-17-month-olds who received it were protected.
Malaria cases appear to be on the rise again after a decade of success in combating the deadly disease.
According to the most recent annual figures, global malaria cases are no longer falling, sparking concerns about its resurgence.
More than 90% of both those who were infected and the 435,000 who died were in Africa. Children are particularly vulnerable.
Malawi, which recorded nearly five million confirmed cases in 2017, has been chosen, along with Kenya and Ghana, to be used in the large-scale pilot of the RTS,S vaccine.