ATLANTA – A booster dose of meningococcal conjugate vaccine should be given to adolescents at 16 years of age if they received a first dose at age 11-12 years, and a booster should be given 5 years after the first dose – up to age 21 years – to those who first received the vaccine at age 13-15 years.
That was the vote of the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention on Oct. 27th, but it was not unanimous. The panel was split 6 to 5, with 3 abstentions. Following that vote, ACIP also voted to include the booster dose under the federal Vaccines for Children program. The CDC usually adopts the ACIP's recommendations but is not obligated to do so.
In 2007, ACIP recommended that the quadrivalent meningococcal conjugate vaccine (MCV4), sold under the brand names Menactra and Menveo, be given to 11- to 12-year-olds at the established preteen visit, and to 13- to 18-year-olds who had not been previously vaccinated.
At that time, it was assumed that this would protect teenagers through the peak age in disease seen in 16- to 21-year-olds, said Dr. Amanda Cohn of the CDC's National Center for Immunization and Respiratory Diseases (NCIRD).
However, recent data have suggested that immunity from the vaccine wanes within 5 years after vaccination, thereby possibly failing to protect those at highest risk, particularly college students living in dorms. “We're missing protecting the group that the recommendation was intended to protect,” Dr. Cohn commented.
A cost-effectiveness analysis presented at the ACIP meeting by Dr. Ismael Ortega-Sanchez, also with the NCIRD, showed that giving just one dose of MCV4 to all 11-year-olds was the least cost-effective of several options the ACIP considered, at $281,000 per quality adjusted life year (QALY).
Giving one dose just to 15-year-olds would cost $121,000/QALY, while giving doses to all 11-year-olds and 16-year-olds – the option chosen – comes to $157,000/QALY.
For comparison, vaccinating all healthy 12- to 17-year-olds against influenza – already recommended by CDC – costs $128,000/QALY, Dr. Ortega-Sanchez said.
Despite the emerging evidence that the current practice of giving MCV4 vaccine to 11- to 12-year-olds is not the ideal option, many panel members and audience members expressed concern about removing the recommendation to give the vaccine at that age since it is part of the now-established preadolescent vaccination visit “platform” that also includes human papillomavirus and diphtheria-tetanus-pertussis vaccinations. Moreover, it does protect those aged 11- to 13-years-old against meningococcal disease.
While the evidence is now clear that the level of protective antibody against Neisseria meningitidis drops to suboptimal levels 5 years after receipt of MCV4, the level of disease does not appear to have been affected yet.
Indeed, “We are currently at historic low rates of meningococcal disease,” Dr. Cohn said, adding that the ACIP working group's aim was to make a change in order to prevent those rates from rising again.
However, the sizable minority of the panel who opposed the addition of the booster dose for 16-year-olds cited cost and lack of cost-effectiveness. Among them was ACIP member Dr. Lance Chilton. “I'm worried that we don't have data that would support cost-effectiveness of a 2-dose regimen. It's certainly better than the current 11- to 12-year only vaccination, but to me the cost-effectiveness data don't justify [the vote],” he said in an interview.
Dr. Chilton of the University of New Mexico, Albuquerque, said he would have preferred simply giving MCV4 at mid-adolescence. “I'm in favor of the preadolescent platform, but I don't think that changing the MCV4 to age 15-16 [years] would appreciably diminish that platform. Adding another platform is probably a good idea.”
As CDC employees, Dr. Cohn and Dr. Ortega-Sanchez have no financial conflicts. Dr. Chilton stated at the beginning of the meeting that he also had no conflicts of interest.