ATLANTA — The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention voted at its summer meeting to expand the maximum ages at which the recently approved infant rotavirus vaccine Rotarix and the established RotaTeq vaccine can be given to simplify and “harmonize” the routine childhood immunization schedule.
The Advisory Committee on Immunization Practices (ACIP) had just voted to add GlaxoSmithKline's infant rotavirus vaccine Rotarix to the schedule.
Rotarix, which was licensed by the Food and Drug Administration in April this year, represents a second oral vaccine option for immunizing infants against rotavirus. Merck's RotaTeq was recommended for routine use in infants by ACIP in Feb. 2006 (MMWR 2006;55[RR-12]1-13).
The two vaccines are equally efficacious, conferring 85%–98% protection against severe rotavirus diarrheal disease and 72%–87% protection against any rotavirus disease. However, they differ in administration schedules: Rotarix is a two-dose series given at 2 and 4 months of age, and RotaTeq is given in three doses at 2, 4, and 6 months. Thus the committee voted to change the maximum ages at which the vaccines can be given to simplify the schedule.
The ACIP did not express a preference for either vaccine, but it did advise the series be completed with the same product whenever possible. If a child switches providers and the product used previously is not available or unknown, the series should be completed with the available product.
Once adopted by the CDC, the new ACIP rotavirus immunization guidelines also are expected to harmonize with those of the American Academy of Family Physicians (AAFP) and the American Academy of Pediatrics (AAP).
Dr. Douglas Campos-Outcalt, the AAFP liaison to ACIP, also expressed support for the recommendation as well as for the availability of a second rotavirus vaccine option: “I think this will make it easier.” He noted that surveys by the CDC and AAFP have found that family physicians have been slower than have pediatricians to adopt RotaTeq in the 2 years since it was licensed, in part because of concerns about cost-effectiveness.
“Hopefully, now that there are two vaccines that are equally effective and equally safe, they'll start competing on price and the cost-effectiveness ratio will [improve],” said Dr. Campos-Outcalt of the University of Arizona, Phoenix.
Both liaisons for the AAFP and AAP said the boards of their respective academies will consider approval of the guidelines once the CDC finalizes them, a process that could take a period of several months for both groups.
Dr. Margaret M. Cortese of the CDC's Division of Viral Diseases, outlined the specifics of the document drafted by a working group and which ACIP subsequently approved. The first dose of either vaccine should be administered to infants aged 6–14 weeks and should not be initiated in those aged 15 weeks or greater. This effectively adds 2 weeks to the 2006 recommendation for RotaTeq, which had said dose 1 should be given at age 6–12 weeks.
The interval between doses should be 4 weeks or greater, and all doses should be given by age 32 weeks. Committee members debated whether the language of the final document should say “8 months 0 days” instead of “32 weeks.” That decision will be made later by CDC. Either way, this would represent an expansion from the Rotarix clinical trials, which used 24 weeks as the maximum age for dose 2, Dr. Cortese said.
Because the oral applicator of Rotarix contains latex and that of RotaTeq doesn't, any infant with a previous severe anaphylactic reaction to latex should receive Rotateq and not Rotarix. The final language also may include a “precaution” about using Rotarix in children with spina bifida, bladder extrophy, or other conditions that predispose to acquiring latex allergy.
The ACIP also voted to include both vaccines for coverage in the federal Vaccines for Children program, per the new recommendations.