British Columbia will join four other provinces and delay part of its seasonal flu shot program this year until after the swine flu shots have been rolled out.
Perry Kendall, the province's chief medical officer of health, says the decision is in part due to concerns raised by an unpublished study suggesting people who got a seasonal shot last year were more likely to catch swine flu this year.
"Obviously that was a significant contributor to the decision," Dr. Kendall told a news conference in Victoria this morning. But, he noted that B.C.'s public health officials had been planning this approach anyway.
The province says it will be offering the seasonal shots starting in mid-October to people 65 and older and to residents of long-term care facilities.
In November, when the pandemic vaccine is available, the seasonal program will be stopped and efforts switched over to giving the H1N1 vaccine.
The study, which has not yet been published, suggests that people vaccinated against seasonal flu are twice as likely to catch swine flu. The paper is still under peer review and its authors can't speak about the findings until it's been published.
Dr. Kendall said he doesn't know if he agrees with the findings, but they can't be ignored. "What we have are respected scientists who have been doing a lot of research in the field for many years in Ontario, British Columbia and Quebec, whose findings support an increase risk."
David Patrick, epidemiologist with the B.C. Centre for Disease Control, said H1N1 cases are already appearing in significant clusters in B.C. In fact, most reported flu cases right now are H1N1 - not seasonal flu. This is what occurred in Australia and New Zealand earlier this year.
"In the southern hemisphere, throughout Australia and New Zealand, there was very little seasonal flu activity and plenty of H1N1 and that's been the case in the northern hemisphere as well," Dr. Patrick said.
He said 98 to 99 per cent of the influenza tests done at the B.C. lab are H1N1. "It's very important to consider that this season … these seasonal viruses are, in fact, H1N1."
Dr. Kendall says the seasonal flu shot program will resume in early 2010.
Ontario, Saskatchewan, Quebec and Nova Scotia are taking similar approaches to flu vaccine delivery this fall.