*These minimum acceptable ages and intervals may not correspond with the optimal recommended ages and intervals for vaccination. See tables 3-5 in the ACIP's General Recommendations on Immunization and ACIP's "Recommended Childhood Immunization Schedule, United States, January-December 1998" for the current recommended routine and accelerated vaccination schedules.

†The total number of doses of diphtheria and tetanus toxoids should not exceed six each before the seventh birthday.

§The booster dose of Hib vaccine which is recommended following the primary vaccination series should be administered no earlier than 12 months of age and at least 2 months after the previous dose of Hib vaccine (Tables 3 and 4 of ACIP's General Recommendations on Immunization).

¶Sequential IPV/OPV, all-OPV, or all-IPV.

**For unvaccinated adults at increased risk of exposure to poliovirus with <3 months but >2 months available before protection is needed, three doses of IPV should be administered at least 1 month apart.

††If the third dose is given after the third birthday, the fourth (booster) dose is not needed.

§§Although the age for measles vaccination may be as young as 6 months in outbreak areas where cases are occurring in children <1 year of age, children initially vaccinated before the first birthday should be revaccinated at 12-15 months of age and an additional dose of vaccine should be administered at the time of school entry or according to local policy. Doses of MMR or other measles-containing vaccines should be separated by at least 1 month.

¶¶This final dose is recommended at least 4 months after the first dose and no earlier than 6 months of age. For children not vaccinated at birth, the recommended interval is first dose at elected date, second dose 1 month later, third dose 5 months after second dose.