The largest Yellow Fever epidemic in decades is hitting the Democratic Republic of Congo (DRC) and Angola, and could soon spread to the Americas, Asia and Europe, Save the Children warns.

The organization’s rapid response Emergency Health Unit (EHU) has deployed to support the DRC’s Ministry of Health with a mass vaccination campaign in the capital city of Kinshasa. The campaign, which begins Wednesday, is part of a last line of defense to stop the deadly virus spreading through the overcrowded city of more than 10 million. 

The virus is a hemorrhagic fever and has claimed nearly 500 lives to date, with thousands of suspected cases. Alarmingly, the World Health Organization warns those figures could actually be 10 to 50 times higher. Yellow Fever is spread by mosquitoes, making rapid transmission in a hot, humid city like Kinshasa very likely, particularly when the rainy season starts next month and mosquito numbers spike.

The outbreak is the largest to hit the region for 30 years and has all but emptied global emergency stocks of vaccines. There are only 7 million emergency vaccines available for this campaign – too few to fully cover Kinshasa, let alone all of the DRC.

“There is no known cure for Yellow Fever and it could go global,” said Heather Kerr, Save the Children’s Country Director for the DRC. “The mass vaccination campaign in Kinshasa needs to take place now so that we can try and stop Yellow Fever from spreading by land and air to more cities in Africa, and across the world.”

Approximately 20 percent of people who have caught Yellow Fever during this outbreak have died. The final stages of the virus can cause bleeding from the eyes, ears and nose, organ failure and a condition known as jaundice, a yellowing of skin and eyes which originally gave the disease its name.

Save the Children’s 11-member rapid deployment EHU is staffed by experts from countries including Italy, China, Korea and the United States. They will support a vaccination campaign run by the DRC’s Ministry of Health, targeting nearly half a million people in Kinshasa for approximately 10 days.

Experts will also provide technical support to Ministry of Health staff by helping to secure the country’s ‘cold chain’: shuttling scarce supplies of vaccines to the vaccination sites while keeping them cold using a network of freezers and cool boxes. In addition, the EHU experts will treat the medical waste resulting from the campaign.

The same team successfully supported the Ministry of Health in vaccinating more than 221,000 people in the town of Boma in western DRC in May.

Following advice from the World Health Organization, Save the Children will provide support for the vaccination campaign that uses just one-fifth of a regular dose – to reach as many children and families as possible with the limited supplies that remain. A full dose of vaccine provides lifetime immunity; the smaller, so-called ‘fractionalized’ dose provides stop-gap immunity for about a year.

“We have to urgently reach as many children and families as we can with the supplies that are left, and this is the only way we are able to do that right now. We can only hope this will be enough to stop the epidemic from spreading any further,” Kerr added.