500
This is the number of different diseases prevented by CDC-recommended childhood vaccines
What is 16? (Full list: Hib, Hep A, Hep B, HPV, Influenza, Measles, Mumps, Rubella, Tetanus, Diphtheria, Pertussis, Meningococcal, Pneumococcal, Polio, Rotavirus, Varicella)