The campaign is being conducted by the international Red Cross federation, the World Health Organization, UNICEF and the Haitian Health Ministry.
A Red Cross statement says the campaign will focus on the capital Port-au-Prince because the disease risk to earthquake victims there is greatest.
The federation said it expects to start by vaccinating about 1,800 people Monday at a camp on the old airport runway and then move on to hundreds of other camps over the next two weeks.
Vaccinations will also be against diphtheria and tetanus.
