Caution Needed Before Starting HPV Vaccination Programs for Girls: Researchers

By SHERYL UBELACKER

TORONTO (CP) – The idea of vaccinating young Canadian females against the leading cause of cervical cancer has been embraced by a variety of public health organizations, but one group of researchers suggests the endorsement of widespread inoculation has been far too hasty.

The vaccine Gardasil protects against four strains of human papillomavirus (HPV), the primary cause of genital warts and the agent behind about 70 per cent of cervical cancer cases.

But researchers led by epidemiologist Abby Lippman of McGill University contend that federally backed provincial immunization programs against HPV are going ahead or planned despite a number of unanswered questions.

“What we’re saying is what I used to tell my children when they had to cross the street: ‘Stop, look and listen,”‘ Lippman said Wednesday from Montreal.

“Stop: We have no epidemic, no crisis, no major problem on our hands,” said Lippman, noting that the number of deaths from cervical cancer is relatively low at 400 per year, and the vaccine doesn’t protect against the cause of 30 per cent of cases.

“Let’s look at the data we have, let’s look for the answers that we don’t have to some important questions that we have, then let’s listen to those data and develop a really perfect program that may or may not include HPV vaccines for certain girls and women.”

Writing in the Canadian Medical Association Journal, in an article published online Wednesday, Lippman and her co-authors say the incidence of cervical cancer deaths has been declining for some time, primarily because of regular Pap smear detection programs.

“In many ways, the predicted 400 deaths per year are a failure of the health-care system to address women’s health needs, either because women aren’t being seen, or they aren’t being offered Pap testing when they are seen, or when they have the Pap test done there is not necessary followup and so on.”

“There should not even be 400 women dying, but we don’t know if we’re going to change those numbers by having a vaccination program, because the vaccine that is available only deals with the virus (strains) that are associated with about 70 per cent of the cancers.”

Even with vaccination, women would still need to have regular Pap smears. But Lippman and others worry that some women will misconceive HPV vaccination as a silver bullet that will give them carte blanche to have as many sexual partners as they want, with little thought for safe sex practices.

“So my question is what’s the goal of the vaccine program? Has anybody defined it? How are you going to know when you’ve got there?” asked Lippman, adding that those most vulnerable to HPV infection – among them marginalized women and homeless teen girls – likely need protection the most but are the hardest for the system to reach.

She said there are a number of unknowns about the vaccine, including how long the immunity it confers lasts and whether at least one booster would be needed. Another issue is whether the vaccine is effective in boys and men – who also can transmit the virus – and should they, too, be getting the shots.

“How can responsible public health people not be curious about having these answers before they move ahead?”

Earlier this year, Ottawa pledged $300 million for provincial programs to vaccinate Canadian females aged nine to 26. In June, Nova Scotia became the first province to announce a program, which will begin this fall with the immunization of about 6,000 Grade 7 girls, who will be offered the recommended three shots of Gardasil over six months. (Three injections cost about $400 per person.)

Jean Riverin, a spokesman for the Public Health Agency of Canada, said the federal body stands by its endorsement of the vaccine.

“We have a vaccine now that’s been tested, we have a vaccine that is available to protect young females that are aged from nine to 26,” he said from Ottawa. “Yes, we are aware that we still need to work and analyze the vaccine and its effectiveness, and . . . we don’t know if we’ll need a booster shot or not.”

But “we have a vaccine now. Let’s fight cancer now. This gives us a period of time to continue forward.”

Widespread immunization against HPV has also been backed by the National Advisory Committee on Immunization (NACI), the Society of Obstetricians and Gynaecologists of Canada and the Canadian Cancer Society.

“It sounds good to protect women, it’s a wonderful political sound bite,” said Lippman. “And it makes me look like I don’t want to protect women. But I’m just saying if we want to advance and really promote women’s health, we need to put it into the context of the lives women lead, how they’re leading it and make sure they understand what they’re getting into.”

“So we just want the public to begin discussing this in a very calm way, so we can have a really good discussion about where this fits into health.”

“All we’re saying is we need some information before we allocate huge sums of already limited dollars to a vaccination program.”

In a companion paper published online by the CMAJ on Wednesday, Ottawa researchers analyzed results from nine studies based on clinical trials and concluded that among females aged 15 to 25, the vaccine “was highly efficacious in preventing HPV infection and precancerous cervical disease” in females not previously infected with one of the four HPV strains it deals with (two of the strains are cancer-causing).

However, the research led by Lisa Rambout of the department of pharmacy at the University of Ottawa did not find evidence that the vaccine reduced cervical cancer cases or deaths.

“Further research is needed to demonstrate efficacy in more representative populations of women and men,” the authors write. “The possible implications of vaccinating against only two oncogenic (cancer-causing) HPV strains must also be considered, as must the duration of vaccine efficacy.”