The Union Health Ministry launched �Mission Indradhanush� last year to immunize children against preventable diseases like diphtheria, whooping cough, tetanus, polio, tuberculosis, measles and Hepatitis B by 2020. The Indradhanush� camp will be organized from May 21 for seven days in Coimbatore, Kancheepuram, Madurai, Thiruvallur, Tiruchirapalli, Tirunelveli, Vellore and Virudhunagar Districts to immunize children and pregnant women.