As part of Canada’s $300-million human papillomavirus (HPV) vaccination program, launched in 2007, your daughter may be offered the shot starting at age nine. Should she get it, or not? The aim is to reduce rates of cervical cancer, which kills some 400 Canadians a year. The vaccine, Gardasil, protects against two HPV strains that cause 70 percent of cervical cancers and two strains that cause 90 percent of all genital warts. It works best if girls get it before they’re sexually active. Most doctors are in favour, but not all are. We asked two to weigh in.
Dr. Abby Lippman
McGill University professor of epidemiology (and former chair of the Canadian Women’s Health Network)
I don’t believe HPV vaccination programs were an urgent need. Most girls and women who get HPV infections will clear them without even knowing they were infected; the body has good defence mechanisms. To get cervical cancer, you would have to have an HPV infection that persists and then causes changes in the cells that are not detected and removed. These changes can be picked up by Pap tests, and probably most HPV-infected women today who go on to develop invasive cervical cancer either did not get tested or didn’t have sufficient follow-up after testing. The Pap is not perfect, but it’s the likely reason rates of death from cervical cancer have dropped markedly in North America.
A systematic, carefully set-up Pap testing program’similar to the mammography program that exists in Quebec (in which everyone over 50 gets a letter reminding them to go for a mammogram)’would mean cervical cancer rates could go down more. There is no such program in place in all provinces, yet the government is willing to put money into the vaccine. [Editors’ note: Eight of the 13 provinces and territories have recommended or started to implement more systematic screening; still, 30 percent of women have not been screened in the last three years.]
Another concern about the HPV vaccine is that it currently protects against only about 70 percent of the HPV types associated with cervical cancer. So, even those who are vaccinated will still need to have a Pap smear. Will those girls have a false sense of security and not have regular tests in future? It’s possible. Relatively few girls from nine to 15 years old were enrolled in trials in which the vaccine was tested for its efficacy, and we still don’t have the full picture of its safety. We also don’t know how long immunity lasts, or if boosters will be needed.
I think there should have been more deliberation before mass vaccination programs started. The vaccine may well be part of the puzzle for how to lower cervical cancer rates. But this cancer should be addressed more fully. Provinces have reduced their budgets for sex education and other programs. Why does the vaccine get priority and other things don’t?
Dr. David Butler-Jones
Canada’s chief public health officer
Making the HPV vaccine widely available is a good idea because it will reduce the number of cancer cases as well as needless cervical cancer deaths. Canada has 1,700 newly diagnosed cervical cancer cases every year. The vaccine means fewer women will need colposcopy [a visual exam of the cervix] and fewer will need to have part of the cervix or the uterus removed as treatment. Thousands of people go to the doctor every year with genital warts’which is a miserable thing to treat’and the vaccine will lower those numbers. We are also finding less common cancers, such as oral cancers, that are related to HPV.
We spend a small fortune to treat things that should never have happened in the first place. So why wouldn’t we prevent as much as we can? The Pap smear is still recommended, but the vaccine will make the test more effective because there will be fewer positive results. It will allow us to focus treatment on what’s left, as opposed to treating something that didn’t have to happen in the first place.
There are a number of people who are harder to reach and tend to get lost in the system. Those at greatest risk of developing cervical cancer and at greatest risk of dying from it are also those least likely to access the system for screening‘people with multiple sexual partners, sex trade workers, people with drug addictions. Immunizing young girls is a great equalizer because whatever their social circumstances are, they have access to this prevention.
In general, we in medicine hold prevention to a higher standard than we do treatment. That’s because you’re dealing with healthy people and you want to be very sure that what you’re doing is a benefit. The number of people immunized against HPV worldwide is in the millions now. The estimates are that you have to immunize about 729 girls with the HPV vaccine to prevent a cervical cancer death. You have to immunize 34,000 people with chicken pox vaccine to prevent a death and 21,000 to prevent one meningitis death. So, relative to many other vaccines, the HPV vaccine is very effective. This is the first vaccine that can prevent a chronic disease like cancer. It’s an exciting new era.
This article was originally titled "Should girls get the HPV vaccine?," in the October 2009 issue of Best Health. Subscribe today to get the full Best Health experience’and never miss an issue!’and make sure to check out what’s new in the latest issue of Best Health.