ATLANTA - To update the harmonized immunization schedule for 1998, the Advisory Committee on Immunization Practices (ACIP) recently voted to change the recommended age for immunization with inactivated poliovirus vaccine (IPV).
The all-IPV schedule is now recommended for administration at 2 months, 4 months and 6-18 months and is consistent with current Food and Drug Administration (FDA) labeling, according to John Livengood, MD, director of the Epidemiology and Surveillance Division, National Immunization Program (NIP).
In January, the FDA approved an amendment for licensure of IPV (IPOL, Connaught) which allows the third dose in an all-IPV schedule to be given as early as 6 months of age; the fourth dose in an all-IPV schedule is still recommended at 4 to 6 years of age.
While the committee unanimously agreed to change the age of administration for the all-IPV schedule, committee members voiced conflicting opinions and eventually voted against changing the sequential schedule. The proposal would have allowed the first dose of oral poliovirus vaccine (OPV) be given at 6-18 months instead of 12 months, the current recommendation.
"It was my understanding that the rationale for using the preferred schedule was the avoidance of OPV exposure. That safety issue still prevails," said ACIP member Mary P. Glode, MD, professor of pediatrics, The Children's Hospital, Denver. "We would weaken that by changing this recommendation."
William P. Glezen, MD, liaison ACIP member from the Infectious Diseases Society of America, said he preferred to eliminate the use of OPV: "I think we are going to improve the health of infants, in general, by delaying or eliminating OPV."
Glezen is a member of the microbiology and immunology staff at Baylor College of Medicine, Houston.
According to data presented by Rebecca Prevots, PhD, Epidemiology and Surveillance Division of the NIP, 20 immunodeficient vaccine-associated paralytic polio (VAPP) recipient cases were reported between 1980 and 1994. However, none of these cases had immunodeficiency diagnosed prior to administration of OPV. Twelve cases of VAPP occurred in children under 12 months of age and eight cases occurred in children 12 months of age and older, Prevots said.
"There were patients at 12 and 18 months of age when they were diagnosed; so the earlier age would not have had an effect," said Samuel A. Katz, chairman emeritus of pediatrics at Duke University, Chapel Hill.
ACIP member Jessie L. Sherrod, MD, agreed with Katz: "I think not only does it provide intestinal immunity at an earlier age, but it also simplifies the schedule. In addition, children tend to stay more up to date on immunizations during their first year, and aren't as compliant the second."
Sherrod is an assistant professor of pediatrics at Charles R. Drew University School of Medicine and Science, Los Angeles.
The recommended sequential schedule remains the same: two doses of IPV at 2 months and 4 months and two doses of OPV at 12 to 18 months and 4 to 6 years.
The committee also voted to alter the recommendations for measles-mumps-rubella (MMR) and hepatitis B (HepB) vaccinations by adding new wording about catch-up vaccination.
The MMR recommendation now states, "Those who have not previously received the second dose should complete the schedule no later than the 11 to 12 year visit."
In conjunction with the recently modified Vaccines for Children resolution expanding HepB coverage, the ACIP also updated the harmonized immunization schedule to reflect the change.
The HepB recommendation now includes a statement about catch-up vaccination and states that all children under age 18 years should receive three doses of the vaccine.
"This would not change the location of the bars, indicating our support for the infant schedule, or the catch-up period at the 11- to 12-year-old visit, but would emphasize the intent of the committee to vaccinate children whenever you access them during the health care process," Livengood said.
Committee member Chinh T. Le, MD, staff physician at Kaiser Permanente Medical Center, Santa Rosa, Calif., suggested changing the language concerning catch-up vaccination.
"Vaccines are listed under the routinely recommended ages. Bars indicate the range of acceptable ages for immunization. Catch-up immunization should be done at any visit when feasible. Shaded ovals indicate vaccines to be assessed only if necessary at the pre-adolescent visit," Le suggested.
The American Academy of Pediatrics and the American Academy of Family Physicians have endorsed the updated schedule. The schedule becomes effective Jan. 1. 1998.
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