Saskatchewan is considering suspending its seasonal flu vaccination program. (Greg Baker/Associated Press)

Saskatchewan's minister of health is rethinking whether people should get two flu shots, in light of preliminary research suggesting a seasonal flu shot may increase the risk of getting swine flu.

Last week, the province was recommending people get both shots — a seasonal shot first and, about a month later, a shot for H1N1, the swine flu virus.

But now the Saskatchewan government is considering cancelling the seasonal shot for many people, said Don McMorris, minister of health.

"Well, right now we know that the most vulnerable for the seasonal flu are 65 and over, in long-term care, and so that I can't see us moving away from that," he said.

"Now the rest of the population — the general population — we may look at suspending the seasonal flu immunization until after H1N1," said McMorris.

Don McMorris, Saskatchewan's minister of health, says the province may suspend administering seasonal flu shots for the general population. (CBC)

Another factor the government is considering is whether H1N1 may overtake the seasonal flu, making seasonal shots a non-issue in the coming flu season.

A decision about whether to suspend the seasonal flu shot program will be made within the next week or so, McMorris said.

"I think if somebody came and insisted on a seasonal flu shot we would certainly say 'yes,' but as far as a mass immunization — which we try to do each fall — that wouldn't be the initiative."

WHO investigates

Normally, the seasonal flu shot is administered in October. In Saskatchewan, a number of people receive the shot free of charge, including seniors, babies, pregnant women, people in long-term care and those with chronic conditions.

Health officials across the country are also considering suspending seasonal flu vaccination programs.

A panel of experts will look at unpublished Canadian data that suggest previous seasonal flu shots may put people at greater risk of catching swine flu, the World Health Organization said Thursday.

The UN health agency has already contacted researchers worldwide to try to corroborate the preliminary Canadian findings, but the effect has not been seen elsewhere, Marie-Paul Keany, WHO's vaccine research director, told a teleconference with reporters from Geneva.

The Canadian research looked at four studies involving about 2,000 people in Canada, health officials told CBC News. Researchers found people who had received the seasonal flu vaccine in the past were more likely to get sick with H1N1.