Health officials attribute the possible outbreak to suboptimal immunisation coverage and the importation of the virus.
The campaign targets a total of 755,011 children under the age of five across Mandera, Wajir, and Garissa counties.
The 10 high-risk counties include Mandera, Wajir, Tana River, Lamu, Kitui, Machakos, Kiambu, Kajiado, Nairobi, and Garissa.