Young women immunized as girls against the sexually transmitted human papilloma virus (HPV) have a significantly reduced risk of potentially cancerous cervical abnormalities, according to a study published Monday in the Canadian Medical Association Journal. In a study of more than 10,000 subjects, Alberta researchers found that young women who took the HPV vaccine were 50 percent less likely to develop cervical-cell anomalies than women who hadn’t been vaccinated. Furthermore, women who had three doses of the quadrivalent vaccine, which protects against four subtypes of the virus, appeared to be less at risk than women who had only two doses of the vaccine. Two of the HPV subtypes that the quadrivalent vaccine guards against are believed to cause 70 percent of cervical cancer cases.
Canada’s National Advisory Committee on Immunization (NACI) recommends that children between the ages nine and fourteen take two separate doses, six to 12 months apart, of Gardasil, a quadrivalent vaccine, and Cervarix, a bivalent vaccine that immunizes against two subtypes of HPV that can cause cervical malignancies. NACI has estimated that without vaccination 75 percent of sexually active Canadians will contract HPV at some point during their lifetime.
The study also found that women who had been immunized against HPV were more likely to undergo Pap smears to screen for cervical cancer. While little research has been done to determine why that is the case, the lead author of the study, Dr. Huiming Yang, medical director of screening programs at Alberta Health Services, speculated that perhaps mothers who vaccinated their children would be more likely to inform them of the risks of cervical cancer.
Read the full story at The Globe and Mail.