Canada ready to vaccinate against human papillomavirus

Jul 19 2006

Canadian women will soon be able to access the first vaccine to protect against the sexually transmitted virus that causes cervical cancer.

The vaccine Gardasil, protects against infection from four strains of human papillomavirus (HPV) which are known to cause about 70 per cent of cases of cervical cancer as well as cancer of the vulva and vagina and genital warts.

Gardasil will be available to Canadian women within weeks following health authorities initial approval for the vaccinating of females aged nine to 26.

Further studies are apparently being conducted to assess the vaccine's effectiveness in older women and in men, who can develop cancer of the anus and penis as a result of HPV infections.

Dr. Michael Shier, head of gynecology at Toronto's Sunnybrook Health Sciences Centre, says they are targeting women because it is they who carry the burden of the disease throughout the world; it seems one woman dies every two minutes of cervical cancer.

Shier says that last year 400,000 Canadian women had abnormal cervical cells linked to HPV that were identified by a Pap smear.

Gardasil manufacturer Merck says the vaccine will enter the market by the end of August and will cost about $135 per dose; three doses given over a six-month period are needed for full immunity to the four HPV strains.

At present women will have to pay for the vaccine but Canada's National Advisory Committee on Immunization (NACI) will decide by the end of the year whether provinces and territories should fund mass immunization programs.

Gardasil was granted approved by the U.S. Federal Drug Administration last month for the same age group of females but the FDA says it is unclear how long the vaccine's protection will last or whether booster shots will be necessary.

The Canadian Cancer Society estimates that 1,350 Canadians will be diagnosed with cervical cancer this year and the disease will kill almost 400.

Worldwide, there are about 500,000 new cervical cancer cases a year and about 250,000 women die from the disease.

Many experts have welcomed the vaccine with some saying for women it is the first big innovation since the Pap smear was introduced six decades ago.

Human papillomavirus is a highly contagious agent transmitted primarily through skin-to-skin sexual contact.

Most Canadian women of reproductive age will be exposed to HPV in their lifetime, of which there are more than 100 strains, some of which cause cancer and others that cause genital and anal warts.

Often, a person can be unaware he or she is infected with the virus because there are no signs or symptoms.

Health experts are emphasising that it will take decades before all women can be protected from HPV infection, and women will still need to continue regular Pap tests, despite the vaccine's approval because not all of the cancer-causing strains of the virus are in the current vaccine.

Senior medical experts say preventing cervical cancer by large-scale vaccination is the ideal cancer control approach and the vaccine could conceivably be administered through school-based inoculation programs, such as those currently in place to protect children against hepatitis B and other infectious diseases.