Republican presidential candidate Michele Bachmann may have railed recently in opposition to vaccinating schoolgirls against the cancer-causing human papilloma virus (HPV), but experts who advise the US Centers for Disease Control and Prevention (CDC) seem prepared to up the ante.
Today, on a vote of 13 in favor with one abstention, the CDC’s Advisory Committee on Immunization Practices said that 11- and 12-year-old boys, like their female counterparts, should receive the series of three immunizations against the virus, which infects some 20 million Americans and causes cancer of the cervix, vulva, vagina, penis, and anus as well as genital warts. Studies like this one in The New England Journal of Medicine also implicate HPV as a cause of oropharyngeal (throat) cancer.
The committee, whose recommendations are widely expected to be signed off by top CDC officials in coming months, said that the vaccinations could begin in boys as young as nine years old, and that 13-to-21-year-old males who have not been vaccinated should receive catch-up vaccinations.
Anne Schuchat, the director of the CDC’s National Center for Immunization and Respiratory Diseases, called the vote a “milestone in the nation’s battle against cancer.” Noting that the virus strains covered by the vaccine are responsible, for instance, for 80% of anal cancers, she added: “The committee did feel that the burden of disease in males justified routine vaccination. They felt there was likely to be additional benefit to girls and women by reducing the spread of the virus.”
Because the virus is so widespread, it is less and less effective to vaccinate as young people get older and become sexually active; in addition, the body’s response in terms of generating antibodies to HPV is strongest at age 11 or 12, Schuchat said.
The vaccine is made by Merck and marketed as Gardasil. The company put out this press release after the vote today. The Food and Drug Administration approved Gardasil for preventing genital warts in young females and males in 2006 and 2009 respectively, and anal cancer in both sexes in 2010.
The CDC recommended that all 11- and 12-year-old girls be vaccinated in 2006, the same year that FDA first approved Merck’s vaccine. But uptake has been hampered by opposition from conservatives like Bachmann who protest against the social message sent by vaccinating children against a sexually transmitted disease. In a report released this month, the CDC noted that, between 2006 and 2010, just 32% of girls aged 13 to 17 in the United States had received the full 3-dose vaccine series. By contrast, coverage rates in Canadian jurisdictions in the first year the vaccine was made available in public schools varied from 85% in the Atlantic provinces to 51% in Ontario.
Today’s vote is significant economically as well as for public health, in that health insurers are less likely to pay for the $130-per-dose vaccination in boys if it is not recommended by the CDC. In addition, a CDC recommendation gives pediatricians the go-ahead to urge vaccination, which is important for uptake. Schuchat noted that, although the CDC in 2009 issued a “permissive” recommendation for boys — a lukewarm endorsement that says boys “may” receive the vaccine — just 1.5% of 13- to 17-year-old boys had been vaccinated by 2010.
Schuchat said that the ACIP felt confident in moving to a universal recommendation for boys because of additional data that has emerged since 2009. This includes FDA’s approval of Gardasil’s use against anal cancer in both males and females, and because of a growing, robust safety database. Nearly 40 million doses of the vaccine had been given in the US by mid-September, with side effects that include headache, soreness at the injection site and mild or moderate fever, dizziness, nausea, and fainting.
The hope among CDC officials, Schuchat added, is that by recommending universal vaccination for 11- and 12-year-olds, uptake in both boys and girls will improve. Even if it does not result in better coverage among girls, vaccinating boys is expected to indirectly protect girls by lowering HPV transmission rates.