False.

Vaccines protect against 12 potentially serious diseases: measles, mumps, rubella (German measles), diphtheria, tetanus (lockjaw), pertussis (whooping cough), polio, Haemophilus influenzae type b (Hib disease), hepatitis B, varicella (chickenpox), hepatitis A, and pneumococcal disease. At least one shot is needed for each of these diseases, and for some of them several doses are required for the best protection. This adds up to a lot of shots, and several are usually given at the same time. Some parents worry that it is not safe to give several shots at once, that they may not work as well, or that they will overload the child’s immune system. But studies have shown these fears to be unfounded. Vaccinations are just as safe and effective when given together as they are when given separately. The immune system is exposed to many foreign substances every day and will not be overburdened by vaccines.