Malawi is rolling out a malaria vaccine pilot programme for children on Tuesday in a bid to prevent the disease which kills hundreds of thousands across Africa each year.
The RTS,S vaccine, the first to give partial protection to children, trains the immune system to attack the malaria parasite, which is spread by mosquito bites.
After more than three decades in development and almost $1bn in investment, the cutting-edge trial is being rolled out in Malawi's capital Lilongwe and then in Kenya and Ghana next week.
Children between 5 months and 2-years-old will be inoculated, and according to the WHO, the vaccine will reach some 360 000 children per year until the end of 2022 across the three countries.
Malawi, Kenya and Ghana were picked for the trial due to the high number of malaria cases in these countries.
"There are over 250 000 deaths of children in Africa every year because of malaria," Mary Hamel, the coordinator for the Malaria Vaccine Implementation Programme at the World Health Organisation told the DPA news agency.
"It's intolerable, the devastating effect for the families, societies. It's the potential to save so many children's lives that makes this vaccine so exciting."
'Provides partial protection'
The protein-based RTS,S vaccine went through five years of clinical trials on 15 000 people in seven countries.
In one clinical trial, children who received doses of the vaccine had a lower chance of developing malaria, the WHO says, as well as of developing severe malaria.
A study showed that the innovative vaccine prevented about four in 10 malaria cases among children and "overall, there were 29% fewer cases of severe malaria in children who received the vaccine".
Hamel said that while the vaccine wasn't a perfect solution, the "WHO expects this vaccine could have considerable impact".
"It is the world's first malaria vaccine that has been shown to provide partial protection against malaria in young children."
These sentiments were echoed by Pedro Alonso, director of WHO's Global Malaria Programme, who said: "The fight against malaria is one where we use imperfect tools; only when we combine them can we achieve great impact. This malaria vaccine adds a tool to our toolkit," he told DPA.
"This vaccine will be rolled out at a time when progress in the global malaria response has stalled," he added, noting that a resurgence of the disease has been seen in some countries that had once achieved great progress.