The CDC's Advisory Committee on Immunization Practices has approved draft recommendations for routine vaccination of 11- and 12-year-old boys with Gardasil to protect against four strains of the human papillomavirus (HPV).
The committee also recommended that boys and young men ages 13 through 21 should be immunized with the quadrivalent vaccine against the virus if they missed an earlier vaccination, according to Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases.
The recommendation, if formally accepted by the agency, would in a single stroke double the number of children who should get the three doses of the vaccine, since it is already part of the recommended list of shots for girls 11 and 12.
But, Schuchat told reporters in a telephone press conference, the uptake of the vaccine among girls has been "disappointing" and one reason the committee added young boys to the list was in the hope of easing the burden of disease on females.
"In addition to providing direct benefit to boys by preventing future genital warts or anal cancer," she said, "there's also the potential that vaccinating boys will reduce the spread of HPV from males to females."
"Male vaccination is most cost-effective when coverage of females is low," she added.
The vaccine has been available to boys and men to the age of 26 since 2009 on a permissive basis, but the new recommendations are "much stronger," Schuchat said.
One reason to strengthen the recommendations, she said, is that the new data have shown "very striking" clinical efficacy in preventing high-grade anal intraepithelial neoplasia, the precursor of anal cancer.
The committee was also reassured, Schuchat said, by expanded safety data based on the use of about 40 million doses up until mid-September.
Schuchat said the committee decision now goes to the CDC for development and publication of formal recommendations. The agency usually accepts committee decisions, she said, and publication follows within a few months.
"The age of 11 or 12 is a very good time to be vaccinated – antibody or immune responses are the strongest – and that's well before girls or boys would become sexually active," she said.
"We know parents are confused about when they ought to be vaccinating their daughters and we hope to improve that messaging going forward," she said.
The original FDA licensing of the vaccine for use in boys and men was to prevent genital warts and last year the licensure was expanded to include the prevention of anal cancer in both males and females.