New Concerns over HPV Vaccine

Vancouver's chief medical officer wants to begin 'mass use.'

By Danielle Egan 31 May 2007 |

Danielle Egan is a contributing editor on The Tyee.

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Humanen Papillom-Virus (HPV).

Unless you've been practicing strict media abstinence over the past six months, you've probably heard that a sexually transmitted virus called HPV (human papilloma virus) causes some cancers, including cervical cancers. And that a pharmaceutical giant, Merck, rolled out an HPV vaccine called Gardasil last summer to immunize against some strains of the virus.

But is that HPV vaccine actually safe and effective for curbing cervical cancers? Some policy-makers and some medical specialists say, "Yes." Other doctors, cancer researchers and the mother of a 14-year-old paralyzed after receiving an HPV vaccination say, "No." But despite the disagreement in the medical communities, Canada has given the vaccine a green light for use on girls as young as nine.

The vaccine has many fans. Canada's Public Health Agency, for example, has endorsed the vaccine as highly effective, and media reports have been overwhelmingly enthusiastic, repeating clinical trial data that Gardasil eliminates the risk of the two most common types of the virus believed to cause 70 per cent of all cervical cancers. Twenty four U.S. states have since pushed for mandatory HPV vaccination, and Virginia has already passed a law requiring vaccination before junior high.

Dr. John Blatherwick, chief medical officer of Vancouver Coastal Health, is so impressed with the scientific data that he'd rather not wait for health policy recommendations from a Health Canada Immunization Committee (due by the end of 2007) and would like to start a mass vaccination program for B.C. girls this September. "We've entered a brave new world in medical science," he says of the Gardasil vaccine. "The studies have been rigorous and I think it's ready for mass use."

Trial shadows

But casting shadows over such confident claims are just-published Gardasil clinical trial studies and recent medical journal editorials stating that the vaccine only reduced the risk of precancerous abnormal cells by 17 per cent, and that, in fact, people who are vaccinated might be at risk of picking up twelve other high-risk strains of HPV not covered by the vaccine.

Cancer researchers and advocacy groups stress that Pap smears still remain the most effective way to curb cervical cancer rates and that HPV testing might cause girls and women unnecessary anxiety since most HPV infections will clear without incident. They also point to other less thoroughly researched risk factors for cervical cancer, like smoking and diet.

Fueling the controversy even further is whether girls should receive the vaccine years before they become sexually active, particularly since recent data from the U.S. Center for Disease Control (CDC) has also uncovered over 1,600 adverse effects among Gardasil-vaccinated people in the general population, including 371 serious reactions.

Dr. Karen McCune is one of the medical experts who has concerns. "I have two daughters who are the right age for this vaccination and I'm going to wait for more information," she says. McCune is a professor of obstetrics at the University of California San Francisco, and recently co-authored a recent New England Journal of Medicine paper questioning the effectiveness of the vaccine. The Paper points out that since it typically takes decades for cervical cancer to develop, Merck's three-year clinical trial tracked the development of lesions indicating abnormal cells, including grade 1 lesions that are typically benign and disappear without treatment. In McCune's opinion it is "insufficient to infer" that Gardasil is effective in curbing high-risk genital cancers.

Pap power?

Approximately 80 per cent of us will contract one of over 100 strains of HPV without even knowing it, and the virus will typically disappear within a year to three years. In comparison, the cervical cancer mortality rate is approximately two women per 100,000. "The potential risks [of the vaccine] outweigh the potential benefits," according to McCune. Those risks are that Gardasil could make women more vulnerable to the HPV strains not covered by the vaccine.

Pap tests therefore remain the most effective way of preventing cancers, in her opinion. "Too often, marketing trumps science," says McCune, citing a recent Oprah Winfrey show in which a doctor claimed Gardasil protects against 99 per cent of cervical cancers. "That's just wrong and there are too many unanswered questions here."

New Gardasil trial data published in the same May issue of New England Journal of Medicine stated that the vaccine was 100 per cent effective at blocking four strains of HPV. While it reduced the development of cervical lesions by only 20 per cent, the researchers concluded that "in young women" the vaccine "significantly reduced the incidence of HPV-associated" vulvar and cervical precancers.

But the study also showed that more vaccinated than non-vaccinated trial participants with types of HPV not covered by the vaccine developed serious lesions. And the FDA also questioned Gardasil's efficacy last May before approving the vaccine, acknowledging that in some patients with other strains of HPV, Gardasil potentially enhanced disease among those with persistent HPV infections and caused higher grade lesions that "might offset the overall clinical effectiveness of the vaccine."

'Not a cure all'

How do other researchers answer these criticisms? "The HPV vaccine isn't perfect. It's not a cure-all for cervical cancers and it's not meant to be a replacement for Pap tests," says Dr. Diane Harper, lead investigator of the Merck clinical trial. But since Paps only find abnormal cells after they've developed, Harper thinks a preventive vaccine will reduce the development of abnormal cells and therefore reduce typical Pap-test related follow-up screenings. "That's a huge benefit," says the Dartmouth Medical School professor and director of the Gynecologic Cancer Prevention Research Group.

The key issue, in Harper's opinion, is whether girls should be inoculated years before they become sexually active, since they might need booster shots after ten years. So she's uncomfortable with mandatory inoculation of pre-teen girls. "What's being misunderstood is that you have to give it to girls before they have sex. That's not true." She says as long as they're not currently infected with one of the four HPV strains Gardasil protects against, they will benefit from the vaccine if they contract them in the future."

But there are further questions about the link between HPV and cervical cancers. A 2003 paper by the National Cancer Institute (NCI) acknowledged even if someone has HPV they might not develop cervical cancer. And even if someone has cervical cancer, they might not have HPV.

Smoking out the problem

They also had concerns about the two HPV testing methods (DNA and traditional blood tests) and said researchers should also investigate other cancer-causing risk factors like smoking, poor nutrition, birth control pills and socio-economic factors such as poverty. The Canadian Women's Health Network has also linked these cancers not just to HPV but also to stress and other common sexually transmitted infections like chlamydia.

The American Cancer Society says that only "a very small number" of persistent HPV infections are linked to cervical cancers, and warns that women under 30 shouldn't even get HPV tests since "too many" are HPV-positive. Dr. Anna-Barbara Moscicki of the department of pediatrics at UC San Francisco even warned that cancer screening of girls causes "considerable anxiety and psychosexual morbidity" and wonders, "How might this affect their future emotional and sexual development?" Since most lesions will clear without intervention she adds that "we should reflect on the basic tenet of medicine: at least do no harm."

The Canadian Cancer Institute ranks the probability of death from cervical cancer at 0.2 per cent, making it the second lowest ranking cancer threat in Canada. And they stress that any program should "complement" not replace Pap tests, which have reduced cervical cancers by 80 per cent since the 1970s. Seventy nine per cent of Canadian women between 18 and 69 are regularly screened with Pap tests, and 60 per cent of cervical cancers occurred in women who don't get regular Paps.

Worth $2 billion in Canada?

The Canadian Cancer Society thinks the HPV vaccine, which costs $404 for the three required shots, should be available and affordable. Health Canada has already set aside $300 million for mass-HPV vaccination and set up a committee to look at feasibility since research has determined that it would cost $2 billion to inoculate 5 million girls aged nine to 13. They should have recommendations by the end of the year, but according to Alain Desroches of Health Canada, PEI has already decided to start a vaccination program.

In addition to the mixed messages from medical experts, some have raised questions about the vaccine's safety.

"Today Jessica was fit with leg braces," says Rhonda Vega of Gardnerville, Nevada, about her 14-year-old daughter diagnosed with Guillain-Barré Syndrome (a serious auto-immune disorder that can cause paralysis) eight days after receiving a Gardasil shot through a school-based program. Jessica was in geography class on May 10th of this year when she started losing feeling in her arms and legs. Her parents rushed her to the hospital and she was immediately sent to ICU in case the paralysis spread to her lungs. The hospital won't comment on this case, citing patient confidentiality issues and Jessica's current neurologist hasn't responded to queries about her condition.

Side effects?

In a separate clinical trial (of boys and girls aged nine to 15), Gardasil found that 82 per cent of vaccinated kids had adverse events including the onset of arthritis (compared to 67 per cent with the non-aluminum placebo), but researchers claim they weren't vaccine-related.

"The State [department of health] says Jessica's condition is not connected with the vaccine because the Gardasil website doesn't include it in the list of side effects [from trial participants]," says Vega, who had her daughter vaccinated because her own grandmother died of cervical cancer. "But what else can it be?" she wonders, saying that prior to the inoculation, Jessica had been a healthy, "super-athletic" teen who never even came down with colds. "She's staying really positive and taking this as a challenge," adds Vega who prefers not to comment on whether they'll pursue any legal action.

U.S.-based National Vaccine Information Center (NVIC), an advocacy group that calls itself "a leading critic of one-size-fits-all mass vaccination policies," red flagged the Gardasil vaccine before its FDA approval, stating it had "not proven safe for little girls." They cited Merck's monograph on adverse effects among vaccinated trial participants including two cases of rheumatoid arthritis and five cases of arthritis. They were especially concerned about long term effects among girls receiving both Gardasil and a hepatitis B vaccine.

Since the vaccine's approval, the group says it has tracked adverse events through a reporting system, starting with two 16-year-olds vaccinated within two weeks of FDA-approval who were eventually diagnosed with Guillain-Barré Syndrome.

Judicial Watch, a group that investigates government corruption has also collected FDA data about Gardasil through Freedom of Information. They found 1,637 adverse events reports including three deaths related to heart problems or blood clotting and 371 serious reactions. About one-quarter of NVIC's reports have included neurological events including grand mal seizures, movement disorders and blackouts or fainting; one 14-year-old's nose was broken when she passed out post-shot and smacked her head on the floor.

'One less'

And there's another twist. Merck chose to gear down its aggressive "One Less" Gardasil promotional campaign after state politicians began calling for mandatory vaccination programs. Around that time it was reported that the governor of Texas (the first state to push for mandatory school-based programs for grade six girls) was connected to Merck-affiliated lobbyists and had received campaign funding from the that company.

Merck has sold over 4 million doses of Gardasil in the U.S. and as a "blockbuster" drug it's expected to net over $1 billion in sales globally. In 2006 it was the third biggest selling "new molecular entity" in Canada netting $1.9 million.

Merck Frosst Canada told The Tyee that over 80,000 three-shot doses have been sold here, but for competitive reasons, they will not provide exact numbers. GlaxoSmithKline has already developed an HPV vaccine called Cervarix, which was just approved in Australia and may be available here by the end of 2007. Dr. Harper has also worked on the Cervarix clinical trial and says it has "already been shown to have cross-protection against two other high-risk HPV viruses, 45 and 31, not covered with Gardasil."

Here in Vancouver, Dr. Blatherwick is convinced that Gardasil will save lives and is eagerly awaiting B.C. government "logistical" schemes for mass vaccination. "It's disappointing to have to wait, but we'll make sure we do a catch-up next year and get these people later," he says, adding that "you can't wait forever for the perfect vaccine."

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