TORONTO - Ontario will run out of the regular swine flu vaccine by the end of the week, forcing many immunization clinics to close and preventing priority groups from receiving the flu shot, Health Minister Deb Matthews said Wednesday.

She declined to name the day the province will run dry, saying some local health units will deplete their stockpiles faster than others.

"We will be exhausting the supply we have by the end of this week," she said.

Ontario has enough vaccine to immunize 2.2 million residents, which the government plans to do by the end of the week, said provincial health officials. But that isn't enough to vaccinate all 3.4 million people who fall into the high-priority groups.

The province will backstop health units that are running out with an additional 189,000 doses of the regular vaccine it received over the week, said Dr. Arlene King, Ontario's chief medical officer of health. It also has 86,800 doses of the unadjuvanted vaccine intended for pregnant women.

Prime Minister Stephen Harper told the House of Commons that 1.8 million doses of the regular H1N1 vaccine will be shipped to the provinces next week, but King said she hasn't been told when the new supplies will arrive or how much Ontario will get.

"I think it's reasonable to say that it's difficult to plan when you don't know from week to week how much product you're going to get," she said.

"So that is a primary point of disappointment right now and difficulties with planning."

Some local health officials, such as North Bay's medical officer of health, have warned that they will run out of the regular vaccine this week, Matthews said.

That's because Ottawa has dramatically curtailed its delivery of the adjuvanted vaccine just as public health units are ramping up efforts to administer the flu shot to priority groups like pregnant women and young children, she said.

"Right across the province, our public health units are working overtime, they're expanding the hours, they are getting the vaccine out and protecting Ontarians as quickly as they can," Matthews said.

"So the issue is not our ability to deliver the vaccine. The issue right now is supply."

If a local health unit has more vaccine than they can administer to the high-priority groups, those supplies will be "redeployed" somewhere else, Matthews added.

Both the provincial and federal governments will have to work together to address the vaccine shortage, said Premier Dalton McGuinty.

"I think Ottawa is feeling the heat, both from the opposition parties and from their sense of responsibility," he said from Niagara-on-the-Lake, Ont.

"I think they are very likely doing everything that they possibly can to secure as much supply as soon as possible."

Supply of the vaccine hit a snag last week after Quebec manufacturer GlaxoSmithKline switched from making the adjuvanted version of the vaccine -- which contains a booster compound -- to making special unadjuvanted batches for pregnant women.

The changeover apparently slowed production of the H1N1 vaccine more than the drugmaker had expected.

Alberta ran out of the vaccine and is temporarily closing clinics this week. Other provinces have also warned of dwindling supplies.

Opposition parties have accused the Ontario Liberals of bungling the vaccine rollout following the chaotic scenes that unfolded last week at some immunization clinics.

Many people, including pregnant women and children, waited all day to get a flu shot -- sometimes in the rain -- and many were turned away.

"It's been a delivery problem from Day 1," said NDP Leader Andrea Horwath.

"This rollout has been horrendous and the government didn't learn the lessons of SARS around communications or around proper planning."

Last week's problems were "unacceptable," Matthews said, but the province is still on track to have more than two million people immunized by the end of the week.

It's unclear how the province will achieve that ambitious goal in just a few short days, as officials will only confirm that "several hundred thousand" people have received the flu shot since the rollout began last week.

"They don't really have a handle on how many (shots) have actually been delivered to this point," said Conservative health critic Christine Elliott.

"That's a huge gap between several hundred thousand and 2.2 million. So I don't think it's a supply problem. It's very much a delivery problem."

Matthews hinted that the province may add school-age children to its list of priority groups once the vaccine supply increases, which Saskatchewan has already done.

But she acknowledged that the province won't meet the target set out in its pandemic plan to have everyone who wants the shot immunized within four weeks.

Ontario has seen 37 swine-flu related deaths since April, including the deaths of an infant and two seniors, all from the London, Ont., area, announced on Wednesday.

"The death of this two-month-old infant is the first recorded in Ontario of a child under the age of one year," the Middlesex-London Health Unit said in a release.

King said 108 people have been hospitalized with H1N1 and 65 of those 108 are in intensive care.