A recent study led by researchers in BC has determined that two doses of the human papillomavirus (HPV) vaccine provides the same protection from HPV as three doses – the previously recommended dosage. Based on these results, the immunization schedule for HPV has been changed in BC to two doses given to grade six girls, followed, if necessary, by a third dose five years later.
Principal investigator for the HPV vaccine clinical trial was Dr. Simon Dobson from the Vaccine Evaluation Centre at BC Children’s Hospital. The study also involved researchers and subjects in Quebec and Nova Scotia.
“What we did was compare the antibody response from two-doses versus three-doses of the vaccine,” says Dobson, adding that no difference in response was found between the two protocols.
“Our results gave confidence to BC policy makers to change the HPV vaccine program to a two-dose schedule,” says Dobson. “As a precaution we’re holding the third dose in reserve in case we find the vaccine needs a boost in future.”
The HPV vaccine has been given every year to BC girls in grades six and nine since 2008, when about 31,000 girls received three doses of the vaccine, spread throughout the year. At a cost of about $100 per vaccine dose, reducing the schedule to two doses could result in a substantial cost saving to the province’s immunization program. Furthermore, elimination of the third dose would also reduce the work load for public health nurses and delivery costs for the program.
“To be able to link the vaccine registry at BCCDC with the cancer registry at BC Cancer… positions BC as a leader in the world for doing this sort of research.”
Dr. Simon Dobson, clinical investigator
Vaccine Evaluation Centre
BC Children’s Hospital
In BC, co-investigators for the study included researchers from the Women’s Health Research Institute, which hosts the HPV research group, BC Centre for Disease Control, which provided epidemiology and evaluation expertise, and the BC Cancer Agency, which provided essential data from the agency’s centralized registry of cancer for ongoing evaluation of the new two-dose program. Another element of the study involved PHSA Laboratories, which developed new tests for measuring the performance of the vaccine.
By cooperatively engaging scientists from a variety of disciplines across different PHSA agencies, and by linking with the efforts of researchers in other provinces, Dobson says the study proved to be “a tremendous success,” and has established a promising pathway for future work.
“The shape of the future is the ability to do data linkages,” says Dobson. “To be able to link the vaccine registry at BCCDC with the cancer registry at BC Cancer… positions BC as a leader in the world for doing this sort of research.”
Dr. Simon Dobson is a clinical investigator at the Vaccine Evaluation Centre at BC Children’s Hospital and a clinical associate professor in the Department of Pediatrics at the University of British Columbia.