More than 800,000 children are to be targeted for vaccination in the Democratic Republic of Congo, after a measles outbreak killed more than 3,500 people this year.
The World Health Organization (WHO) and the Congolese government aim to carry out the emergency programme across the country in slightly more than a week.
The WHO says the epidemic is the world’s largest and fastest moving. It has killed more Congolese people this year than Ebola.
Despite previous rounds of immunizations, the disease has spread to every part of the country. Lack of routine access to vaccinations and healthcare has contributed to the problem.