Children in rural South Sudan died as a result of a bungled vaccination campaign to combat measles, the United Nations and South Sudan's government announced on Friday.

South Sudanese Health Minister Riek Gai Kok expressed "deep regret and sadness" at the deaths of the 15 children, who lived in the rural, south-eastern village of Kapoeta.

An investigation into the deaths supported by the World Health Organization (WHO) and the UN children's fund UNICEF found that the children died as a result of "the administration of a contaminated vaccine."

Around 300 children up to 5-years-old were treated during the four-day campaign which saw the local team using a single reconstitution syringe to mix multiple vaccine vials. The UNICEF-supplied vaccines were also kept in a building with inadequate refrigeration.

Another 32 children suffered from fever, vomiting, and diarrhea, but were able to recover from their symptoms, a joint statement from the WHO and UNICEF said.

Children administering vaccines

Although local teams had been trained by development partners and the WHO, the investigation showed that local officials failed to follow immunization guidelines.

"We have to look into why the training was not passed on to the teams on the ground," said WHO spokesman Tarik Jasarevic in Geneva.

South Sudanese Health Minister Kok also noted that the team that administered the vaccines was not well-trained.

"The team that vaccinated the children in this tragic event were neither qualified nor trained for the immunization campaign," Kok told a news conference.

The untrained team also recruited two children aged 13 and 12-years-old to administer the vaccines, the health minister added.

The risk of measles remains high in South Sudan due to an ongoing military conflict that has killed tens of thousands and seen almost 2 million people flee the country. According to the UN, the country has suffered from measles outbreaks caused by a backlog of unvaccinated children.

rs/bw (AP, AFP, dpa, Reuters)