Manitoba's top doctor, Joel Kettner, said Tuesday he understands the confusion doctors and patients are having over flu vaccinations. He's pledged to give doctors the answers they need by Wednesday.

Manitoba is following the lead of Ontario, Saskatchewan and British Columbia in modifying its seasonal flu vaccination campaign.

But the move is causing confusion as Winnipeg doctors said they're struggling with what to tell their patients.

Provinces have been reviewing their vaccination plans since Canadian researchers announced last week that preliminary results of a study suggest people who had received the seasonal flu vaccine in the past were twice as likely to get the pandemic swine flu virus. The research has not yet been peer reviewed or published.

Manitoba's chief medical officer of health, Joel Kettner, said his decision was motivated by that study.

"Manitoba is taking a cautious, phased-in approach to seasonal flu vaccination this year while the study's findings are assessed and other information is analyzed, including Manitoba's own data," the province said in a news release Tuesday. "The Public Health Agency of Canada has stated that an expert panel is reviewing the study."

The provincial seasonal flu vaccination campaign will now be aimed only at people older than 65 and residents of long-term care homes or those who have chronic illnesses.

Kettner also suggested Winnipeggers not get seasonal flu shots at the massive clinics the city plans to hold. City health authorities announced last week they would hold mass clinics over the space of three days in mid-October.

The Winnipeg Regional Health Authority (WTHA) aimed to immunize 24,000.

Doctors, patients scratching their heads

Winnipeg family doctor Darcy Johnson told CBC News his staff called the WRHA to co-ordinate delivery of the seasonal flu vaccine and were told the program had been suspended.

"This has been very stressful for physicians and for our staff. They've been getting continual inquiries from patients," Johnson said.

Another local family physician, Dr. Mike Dillon, said he feels doctors have been left out of the loop.

"It's difficult to know what we're supposed to do and recommend to our community because the rules seem to be changing every few minutes or every couple of days anyway. It puts us in a bit of a difficult position because oftentimes patients have heard stuff before us," Dillon said.

Kettner told CBC he understood the confusion but promised physicians would be receiving a letter from Manitoba Health detailing the changes within one day.

Other Manitobans will be given the seasonal flu vaccine later, possibly after the end of the vaccine campaign against the H1N1 influenza A virus, which causes the strain of swine flu currently circulating around the globe. The H1N1 vaccination is expected to take place in November, Kettner said.

"Manitoba has increased its surveillance for influenza and other causes of flu-like illnesses this year so the flu strategy can be adapted appropriately," the press release said. "The province will continue to provide Manitobans with updated public health advice."

The H1N1 flu virus is expected to be the main flu strain circulating in Manitoba over this fall and winter. Seniors have been most at risk for complications from seasonal flu while younger people have been more at risk for complications from H1N1, the press release states.

"People of all ages with chronic or other health conditions of concern should consult with their health-care provider about whether they need one or both vaccines," the province said. "Manitoba's H1N1 vaccine prioritization list will be released soon, and it is expected the vaccine will be available this fall."

Information about seasonal and H1N1 flu and the provincial vaccine campaigns is available on the Manitoba government website.