The World Health Organisation (WHO) has described this as a “milestone” for the four countries.

WHO Director General Dr Tedros Adhanom Ghebreyesus said "the approval of the Ebola vaccine by these countries is another milestone in the fight against this unforgiving disease."

"Africa has rallied to cement hard-fought progress to keep its people safe from Ebola," he added.

The four countries are Ghana, the Democratic Republic of Congo, Burundi and Zambia.

The vaccine is called Ervebo vaccine. It was manufactured by Merck.

Preliminary study results show that the vaccine has 97.5% efficacy rate.

Data also suggests that vaccinating people who are already infected reduces their chances of dying.

DR Congo is currently battling an Ebola outbreak which has killed 2,249 people since August 2018.