New Delhi Apr. 7: The first phase of the Universal Immunisation Programme 'Mission Indradhanush' will begin in 201districts of the country starting Tuesday. The programme aims to cover all the children below two years of age who haven't been vaccinated or partially vaccinated against diseases like Diphtheria Tetanus Polio Measles Whooping Cough Hepatitis B and Tuberculosis. (Read: 10 vaccines recommended for your child) Out of the 201 high priority districts selected 82 are concentrated in Uttar Pradesh Bihar Madhya Pradesh and Rajasthan. These 201 districts are also home to nearly 50 per cent of all unvaccinated or partially vaccinated children.