Researchers from Dalhousie University are working with the Prince Edward Island Department of Health and Wellness to conduct a new study of the Human Papillomavirus (HPV) vaccine.
“All girls who received the HPV vaccine through the school vaccination program are being invited to help researchers with this study,” says Chief Public Health Officer, Dr. Heather Morrison. “While it is widely accepted among researchers that HPV vaccine can safely protect against HPV disease and will prevent cervical cancer, it is not known how long this protection lasts, or whether there is any difference in effectiveness between two doses or three doses of HPV vaccine.”
“We know that HPV causes cervical cancer, and that the HPV vaccine prevents infection from HPV and reduces the risk of cervical cancer,” says Dr. Shelly McNeil, a lead researcher on the study and infectious disease specialist at Dalhousie University and Capital District Health Authority, Halifax. “What we want to determine is how the two-dose schedule given in some provinces compares to the three-dose schedule given here in Prince Edward Island – and we want to follow girls over the long term to see how effective the vaccine has been over time.”
Currently, Health Canada has approved a three-dose schedule of the quadrivalent HPV vaccine given over six months. This three-dose schedule is offered by Public Health Nurses in Health PEI to all girls in Grade 6. In some provinces in Canada, the vaccine is given as a two-dose schedule.
To determine if a two-dose HPV vaccine schedule provides equivalent protection, the Quadrivalent HPV Vaccine Evaluation Study (QUEST) will follow more than 8,500 teenage girls recruited from British Columbia, Alberta, Quebec and the Maritimes for up to 10 years. The study will assess risk factors, frequency of infection with HPV, and the level of protection provided by two doses of vaccine compared to three doses.
“Letters are being sent to Prince Edward Island girls who received three doses of HPV vaccine since 2007,” says Dr. Morrison. “Over the next several months, all girls who received the HPV immunization in school are being invited to assist in finding out the difference the vaccine makes.”
The Prince Edward Island HPV immunization program has been offered since the 2007/2008 school year.
QUEST builds on earlier HPV vaccine research. In 2006, research conducted in Canada measured the short-term immune response of a two-dose HPV vaccine. QUEST aims to determine if this protection is maintained over a longer term. Dr. Morrison adds, “This study will help optimize our HPV vaccine dosing schedule to ensure the current and future health and well-being of Islanders.”