Parents should follow the vaccine recommendations set by the CDC or the health bodies of their country. Health organizations are very pro-active in approach to vaccination for children as it encompasses the safety issue. Immunizations schedules are periodically revised according to vaccine recommendations which are updated by the respective health organizations. The health bodies need to be referred to for the most up-to-date information on age related matters, number of doses and who should or should not be vaccinated. You can also receive information from hospitals and clinics in your vicinity.