The suspected measles cases have increased from 28 to 40 in two days, say Health officials in Abyei Administrative Area.
Dr Yousif Lel Ayom, Expanded Program on Immunization Manager in the Area says they plan to conduct a mass campaign to help avoid further cases in the area, Radio Voice of Hope reports.
He adds that many cases are being handled at Medicine Sean Frontiers Hospital.
A joint medical team involving WHO, UNICEF and Local authorities have teamed up to make a rapid response to prevent further cases.
Dr Yousif says their rapid response will target more than 35 thousand children during the five days vaccination expected to start on Saturday.
The Area vaccination will take advantage of the dry season to reach all villages during this campaign, says Albino Miyor, Abyei Administrative Area Health Minister.
He says most of those affected by measles are the people who fled the fighting in Unity State over the last two years.
WHO and South Sudan confirmed five cases of measles in 2015, in Bentiu of Unity State, Duk of Jonglei, Wulu in Lakes, Yei and Juba of Central Equatoria States.