TORONTO - The real challenge in the fight against H1N1 will be convincing the general public to get vaccinated despite all the recent focus on long lineups for high-risk groups seeking the shot, Premier Dalton McGuinty said Tuesday.

Public health officials across the province have learned from last week's frustrating lineups for the vaccine, said McGuinty, who's convinced things will go more smoothly moving forward.

The government's biggest concern right now is persuading all 13 million people in Ontario that they need to get vaccinated, he said.

"I think that will be our single, greatest challenge," McGuinty said. "It will not ultimately be the delivery system or the distribution system."

There still seems to be "fairly broad resistance among Ontarians in participating in the vaccination program," said McGuinty.

"It's absolutely essential," that everyone gets the shot, even if it takes until Christmas to complete the program, he added.

Dr. Donald Low, chief microbiologist at Toronto's Mount Sinai hospital, said he agreed with the premier.

Low, who is also head of the public health laboratories with the Ontario Agency for Health Protection and Promotion, said he's heard, among other things, concerns from the public over whether the vaccine has been rushed to market.

The yearly complacency about the seasonal flu shot is also a factor, as is the mistaken belief by some that H1N1 is no worse than the seasonal flu, he said.

"We definitely have seen a spike in interest as the result of the unfortunate death of Evan," said Low, referring to the Oct. 26 death of Evan Frustaglio, 13, of Toronto.

"But I think as that memory kind of fades from the headlines over the next couple of weeks, and when the vaccine eventually becomes available, I think we'll see the numbers drop back down again."

Hundreds of thousands of Ontario residents have already been given the flu shot and the province aims to have 2.2 million people vaccinated by the end of Saturday, said Dr. Arlene King, the province's chief medical officer of health.

But health officials still don't know when there will be enough vaccine to begin offering it to the general public, saying it depends on the supplier.

The company making Canada's H1N1 vaccine said Tuesday it had finished producing a special version of the shot for pregnant women and was again focusing its efforts on the vaccine intended for the majority of Canadians.

GlaxoSmithKline was asked to make special batches of adjuvant-free vaccine for pregnant women. The switchover of production lines at its plant in Ste-Foy, Que., was blamed for slowdowns in this week's delivery of the adjuvanted vaccine across Canada.

Adjuvants are compounds that boost the immune response to the vaccine, allowing lower doses to be used.

The Quebec plant is back to producing the regular vaccine, GSK spokeswoman Megan Spoore said in an interview with The Canadian Press.

If the vaccine doesn't become widely available for the general public until late December, it may be another reason for people to become complacent, Low said.

Ontario has seen 33 swine-flu related deaths since April and 90 people were hospitalized with H1N1 as of Monday, King said during a briefing Tuesday.

Swine flu activity in Ontario is higher than is normally seen at the peak of a normal flu season, and also higher than during the first wave of the virus in June, she said.

"No one has a crystal ball in terms of when this wave will peak or what the peak actually will be," King said.

"Our objective is to try to dampen the peak as much as we can, and assuming we can get very high uptakes of vaccine to prevent a possible resurgent wave later on," she said.

Pandemics typically occur in several waves, King warned.

Low agreed, saying a third wave of H1N1 could come next year, possibly in the spring.

While getting the vaccine provided frustrating for many given long lineups last week, King said health units are getting better at providing the shot.

Much shorter lineups were seen in Toronto on Tuesday after days of chaotic scenes. Many people, including pregnant women and children, waited all day to get a flu shot last week, sometimes in the rain, and many were turned away.

Toronto, like Ottawa and several other cities, is giving appointment times for high-risk people to get the flu shot.

Across Ontario, at least 100 clinics and 2,800 doctors' offices are providing the flu shot.

Priority groups of people most vulnerable to the flu include pregnant women, children under five, health-care workers, caregivers for those who are vulnerable and unable to get the vaccine, people under 65 with pre-existing health conditions, and those who live in remote or isolated communities.