The Canadian Press

People sit outside Toronto's Mount Sinai Hospital on Thursday, June 25, 2009. (CP24/Tristan Phillips)

Toronto Public Health officials say there are three cases of swine flu at Mount Sinai Hospital.

Two staff and one patient on one ward have contracted the H1N1 virus, and officials say the hospital is acting to contain the cases.

Meanwhile, a sharp increase in swine flu cases in the city has seen the vaccination program accelerated, and the general public can begin receiving H1N1 shots next Monday.

Starting tomorrow, high-risk priority groups can begin receiving shots at several clinics around the city.

Priority groups include adults 65 and under with chronic health conditions, pregnant women, and healthy children six months to under five years old.

Dr. David McKeown, the city's medical officer of health, says they expect the clinics to be very busy and they're prepared to extend the hours if necessary.

Officials are urging Toronto residents to wait until Monday and allow priority groups to get vaccinated first.

Initially, the City of Toronto planned to vaccinate health-care workers this week followed by priority groups starting next Monday.