Democratic Republic of Congo (DRC) and Angola declared an emergency mass yellow fever vaccination campaign this week to curb the disease which claimed thousands of lives this year.
It is expected that 14 million people will benefit from the campaign in 10 days with the contributions of World Health Organisation (WHO) and its 56 global partners, including Médecins sans Frontières (MSF), International Federation of the Red Cross (IFRC) and UNICEF.
The mass vaccination began on Monday in Angola.
About 41,000 health workers have been on duty in more than 8,000 locations with 17.3 million syringes.
″Protecting as many people as possible is at the heart of this strategy. With a limited supply we need to use these vaccines very carefully,″ says William Perea, Coordinator for the Control of Epidemic Diseases Unit at WHO.
The campaign aims to prevent potential spread of disease which contact between 84,000 and 170,000 people each year.
Yellow fever an acute viral disease which is transmitted by infected mosquitoes, according to the WHO.
It can cause fevers, vomiting, headaches, back pain and paralysis.
More than 400 people have died of the disease since December.
This emergency campaign launched to end transmission before the rainy season starts in September.
Congo's Minister of Health, Felix Kabange Numbi Kabange, told reporters on Tuesday, "By the end of this vaccination campaign, we are going to put an end to the progression of yellow fever."
Around 2 million people were vaccinated in Kinshasa during campaigns in May and July.
Overall, some 13 million people in Angola and 3 million in Congo have been vaccinated this year.
It is the first time in a campaign fractional doses of the vaccine apply to people in order to stretch limited supplies amid a global shortage.