A campaign to vaccinate tens of thousands of children in eastern Congo’s Masisi Territory continued Monday, as local health authorities battled a measles outbreak that has left thousands of children sick.

Local healthcare workers were supported by MSF teams, who had been called in to support them as the outbreak took off over recent months amid an ongoing conflict that is now one of the world’s largest displaced person crises.

In Rubaya, Silas Bazimaziki Rugiriki came to get his son vaccinated. He said he, like others, had noticed when children in the area started getting sick.

“Since we know the vaccine is necessary and protects the children, we were happy (to bring them here)," he said. "That's why we brought the children so they could receive the vaccine against this epidemic."

The measles isolation ward of the nearby Kachehembe hospital is full of mothers waiting with their young children.

"I thought it was just a fever, but then I realized the child had measles,” said Irène Shashire, a 21-year-old mother of a measles patient.

She said she came to the hospital because she heard treatment was being provided there, and that the measles infection was just the latest challenge she was facing as she tried to take care of her child.

“We lived through the war; we had nothing, no money. We were worried,” she said.

Dr. Toussaint Selemani, MSF’s measles response lead, said that conflict had forced many populations in the surrounding area to relocate, complicating the health system’s response.

“From the point of view of the vaccination campaign, the target population that we estimated, we are now more than that," he explained. "Why? Because there is a population movement."

He added that the region was fighting multiple epidemics at the same time, including cholera and mpox.

Rubaya is home to one of the largest coltan deposits in the world, and the Rwanda-backed rebels that took control of the mine from the Congolese government last year have been accused of funneling minerals out of the country.

The larger Masisi Territory that is home to Rubaya has been under M23 control since the group took large swaths of territory, including eastern capitals Goma and Bukavu, earlier this year.

The rebels’ advance has killed some 3,000 people this year and worsened what was already one of the world’s largest humanitarian crises, with around 7 million people displaced.

While fighting has largely decreased as a result of peace efforts, there are still clashes and civilians are still being killed.

The Democratic Republic of the Congo and Rwanda are due to sign a peace deal on Thursday in Washington.

AP Video by Justin Kabumba