SINCE PUBLICATION of the recommended childhood immunization schedule in January 1997,1 CDC's Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP) have changed recommended ages for administration of measles-mumps-rubella vaccine (MMR) and poliovirus vaccines. In addition, these organizations have clarified recommendations for administration of MMR, varicella vaccine, and hepatitis B vaccine during the routine visit to health-care providers for adolescents aged 11-12 years2; the interchangeability of the three licensed Haemophilus influenzae type b (Hib) vaccines for primary and booster vaccination; and the timing for the third dose of hepatitis B vaccine. This report presents the recommended childhood immunization schedule for 1998 (Figure 1) and explains the changes that have occurred since publication of the last schedule. Detailed recommendations about the use of vaccines are available from the manufacturers' package inserts, the 1997 Red Book,3 or ACIP statements on specific vaccines.
In January 1997, the Food and Drug Administration (FDA) approved an amendment to the package labeling for the inactivated poliovirus vaccine (IPV) currently licensed in the United States, allowing the third dose of this IPV in an all-IPV schedule to be administered as early as age 6 months. Data from clinical trials have demonstrated that IPV may be effectively administered to infants at age 6 months following receipt of IPV at ages 2 and 4 months.4 To reflect this change, the ACIP, AAP, and AAFP have changed the recommended age for administration of the third dose of IPV in an all-IPV schedule to 6-18 months. The recommended ages for administration of poliovirus vaccine in either an all-oral poliovirus vaccine (OPV) schedule or an all-IPV schedule are now the same: 2, 4, 6-18 months, and 4-6 years.
ACIP recommends a sequential poliovirus vaccination schedule consisting of two doses of IPV administered at ages 2 and 4 months, followed by two doses of OPV, with the first dose of OPV administered at age 12-18 months. This schedule may reduce the risk for vaccine-associated paralytic poliomyelitis among immunodeficient infants by allowing more time for diagnosis of immunodeficiency disorders that would contra-indicate administration of OPV.5 The AAP and AAFP give no preference for any of the three acceptable schedules and recommend that, for children who received IPV at ages 2 and 4 months, the third dose of polio vaccine (either IPV or OPV) be administered at age 6-18 months.
The recommended age for the second dose of MMR is now 4-6 years. Additional details, including the rationale for change, will be discussed in the revised ACIP recommendations for MMR.6
The routine visit to health-care providers for adolescents aged 11-12 years remains an important time to ensure receipt of two doses of MMR beginning at or after age 12 months and one dose of varicella vaccine, and that the hepatitis B vaccine series has been initiated or completed. A shaded oval (Figure 1) is used to distinguish this assessment from the need to routinely administer the diphtheria and tetanus toxoids (Td) booster to all children at this age. Additional changes have been made in the wording in the footnote to clarify this difference.
Three Hib vaccines are licensed for infant vaccination: (1) oligosaccharide conjugate Hib vaccine (HbOC) (HibTITER® [Wyeth-Lederle Laboratories, Pearl River, New York]*), (2) polyribosylribitol phosphate-tetanus toxoid conjugate (PRP-T) (ActHIB® and OmniHIB®, manufactured by Pasteur Merieux Connaught, France [Lyon, France] and distributed, respectively, by Pasteur Merieux Connaught, USA [Swiftwater, Pennsylvania] and SmithKline Beecham Pharmaceuticals [Philadelphia, Pennsylvania]), and (3)Haemophilus b conjugate vaccine (meningococcal protein conjugate) (PRP-OMP) (PedvaxHIB® [Merck, Inc., West Point, Pennsylvania]). These products are now considered interchangeable for primary as well as booster vaccination. Excellent immune responses have been achieved when vaccines from different manufacturers have been interchanged in the primary series.7-9 If PRP-OMP is administered in a series with one of the other two products licensed for infants, the recommended number of doses to complete the series is determined by the other product (and not by PRP-OMP). For example, if PRP-OMP is administered for the first dose at age 2 months, and another vaccine is administered at age 4 months, a third dose of any of the three licensed Hib vaccines is recommended at age 6 months to complete the primary series.
For children born to hepatitis B surface antigen-negative mothers, the third dose of hepatitis B vaccine should be administered at least 2 months after the second dose but not before age 6 months. Wording to this effect has been added to clarify the recommendations for hepatitis B vaccine administration.
Recommended Childhood Immunization Schedule—United States, 1998. JAMA. 1998;279(7):495-496. doi:10.1001/jama.279.7.495