What is HPV?
HPV is a sexually transmitted infection (STI). Researchers estimate there are nearly 200 strains of HPV; some of these cause genital warts, while others are identified as cancer-causing. HPV is also extremely contagious: 80 per cent of sexually active adults will come into contact with the virus at some point, according to Dr. Guylaine Lefebvre, president elect of the Society of Obstetricians and Gynaecologists of Canada (SOGC). "It can be spread through skin-to-skin contact, making it different from other STIs," she explains. "Condom use does not mean you're protected."
Though HPV is highly contagious, Dr. Lefebvre says most people's immune systems will fight off the virus without these people ever knowing they were infected. However, last year alone, 400,000 Canadian women had abnormal (precancerous) cervical cells, 14,000 were diagnosed with cervical cancer and 400 women died from cervical cancer. "That's one woman a day who dies in Canada from cervical cancer," says Dr. Lefebvre, adding that 99.7 per cent of all cervical cancers are caused by HPV. Cervical cancer is the number one killer of women in developing countries and develops 10 to 15 years after the initial viral infection.
Genital warts also show up in roughly two per cent of the population. Though they are not inherently life-threatening, genital warts are uncomfortable and embarrassing and create a life-long emotional toll for the carrier.
What does the vaccine do?
The most recent vaccine approved by Health Canada, manufactured by Merck Frosst Canada, is called Gardasil. According to studies, this vaccine is 100 per cent protective against the four most common strains of HPV and was safely administered among women aged 9 to 26. The vaccine prevented the HPV strains causing all genital warts and approximately 70 per cent of cervical cancers, including cancers of the vulva and vagina. Another vaccine from GlaxoSmithKline is still undergoing clinical trials.
The Merck vaccine is administered in three doses over a six-month period at approximately $135 per dose, totalling $405. Though it will be available through family physicians by autumn 2006, provincial funding for the vaccine has not yet been determined, placing the onus on the individual or parent to cover the costs.
In addition, though studies show the vaccine is effective for five years, it is unclear at this point as to whether a booster may be needed after a five-year period.
Finally, the vaccine will not work after an individual has been infected with HPV. For this reason, medical experts feel the vaccine should be given to preadolescent girls aged nine to 12 for maximum prevention and effectiveness.
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Is it risky to vaccinate girls so young?
For parents who worry about overvaccinating their child, Dr. Joanne Embree, vice president of the Canadian Pediatric Society, says complications from the vaccine are very low. "We use less antigen to vaccinate infants and children than we did even 10 years ago, so the risk [of overvaccinating] is minimal," she explains. Immediate side effects from the vaccine were also minimal: soreness at the injection site and muscle tenderness were the most common.
Dr. Embree supports the vaccine in preadolescent girls in spite of the question of its effectiveness past five years. "Young women who acquire HPV in their teens and early 20s are at an increased risk of cervical cell changes and eventually cancer," she says. "Giving the vaccine to preadolescents protects them in a five-year period when they are at the highest risk of adverse consequences. Even if the vaccine does not last [past five years], the benefits are still very substantial."
However, Judy McEachern of Alliston, Ont., a mother of two daughters aged 12 and 15, has very deep concerns about the vaccine's short study period -- subjects were followed for an average of 17 months. "We have no proof of long-term side effects," she says. "If this was something they had studied over 25 years I would feel a lot more comfortable giving it to my girls."
McEachern is also concerned with the implications the vaccine has for young girls, as not all of them will have supportive families to help them understand the issue of sexuality and disease.
In addition, Dr. Lefebvre says it's important to clarify that the HPV vaccine doesn't protect women against other STIs and pregnancy -- and it's still paramount for women, vaccinated or not, to have regular (usually annual) Pap tests to be sure there is no abnormal cell growth.
A good time to discuss sexuality
Regardless of whether parents choose to vaccinate their daughters, both Dr. Lefebvre and Dr. Embree urge parents to take advantage of the issue of the HPV vaccine to talk to their daughters about sexuality, dating, adolescent issues such as drugs and alcohol and an overall healthy lifestyle. "It's hard for parents to comprehend that their nine-year-old daughter is going to have sex, but sooner or later they're going to get there," says Dr. Embree. "Parents can't control who their girls will fall in love with."
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