evidence: Medical and public health experts review available data on newly licensed and existing vaccines. These experts, who include vaccine experts, scientists, doctors, and public health professionals, form the Advisory Committee on Immunization Practices (ACIP). [...] The final vaccine recommendations include the - Number of doses of each vaccine, - Timing between each dose, - Age when infants and children should receive the vaccine, and - Precautions and contraindications (who should not receive the vaccine). CDC sets the immunization schedules based on ACIP's recommendations. The childhood and adolescent schedules are also approved by the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists. The adult schedule is also approved by the American Academy of Family Physicians, the American College of Obstetricians and Gynecologists, the American College of Physicians, and the American College of Nurse-Midwives.