Lawmakers looking to force preteen girls to take Gardasil, a new vaccine against a virus that causes cervical cancer, are targeting the wrong age group, cancer data shows.
Middle-school girls inoculated with the breakthrough vaccine will be no older than 18 when they pass Gardasil’s five-year window of proven effectiveness — more than a decade before the typical cancer patient contracts the sexually transmitted human papillomavirus (HPV).
Infectious disease specialists and cancer pathologists say the incubation period for HPV becoming cancer is 10 to 15 years — meaning the average cervical cancer patient, who is 47, contracted the virus in her 30s and would not be protected by Gardasil taken as a teen.
“It is a delicate balancing act,” said Debbie Saslow, director of breast and cervical cancer control at the American Cancer Society. “If the vaccine is given at too young an age, it may wear off. Yet if it is given too late, it won’t work.”
Merck & Co. is still studying the longevity of Gardasil, the lone HPV vaccine on the market, which won approval from the Food and Drug Administration in June. But that hadn’t impeded its lobbying efforts. Legislators in at least 20 states and cities, including Virginia and the District of Columbia, are considering HPV vaccinations for girls 11 to 13 as a requirement for school attendance. Texas already has done so.
“We are doing further tests and follow-up. But right now, we know it is effective for five years,” said Dr. Richard Haupt, executive director of medical affairs in Merck’s vaccine division.
Gardasil, a $360 series of three shots over six months, protects against two HPV strains that cause nearly 70 percent of cervical cancer cases. It also prevents two other strains linked to 90 percent of genital warts cases.
Merck, which did not respond to repeated requests for its HPV incubation statistics, unexpectedly suspended its lobbying campaign yesterday.
“Our goal is about cervical cancer prevention. … We’re concerned that our role in supporting school requirements is a distraction from that goal,” Dr. Haupt told the Associated Press.
By the numbers
Dr. Joseph Bocchini, chairman of the committee on infectious disease of the American Academy of Pediatrics, says HPV can take up to 20 years to cause cervical cancer.
“It can occur more rapidly, but very commonly, it is a 20-year period before it leads to cancer,” said Dr. Bocchini, whose group has endorsed HPV vaccinations on 11- and 12-year-olds but has withheld support for its mandated use.
Even when applying a longer 20-year incubation period, requiring Gardasil for sixth-grade girls, as nearly all the legislation does, would not prevent the overwhelming majority of cervical cancer cases in the U.S.
American Cancer Society numbers show that from 2000 to 2003, more than 70 percent of cervical cancer patients were older than 40 — still outside Gardasil’s five-year protection window if given to sixth-graders.