CTV News has learned that Montreal's public health agency is planning to alter its vaccination schedule in order to allow young children to get the H1N1 shot sooner than originally planned.

The official announcement is expected to come on Wednesday morning.

Several people in the public health system confirmed to CTV News that the Montreal vaccinations scheduled for Friday Nov. 6 for families with babies under 6 months, along with people with weak immune systems and their family members, will instead take place one day early, on Thursday, Nov. 5.

Additionally, children under the age of 5 -- originally scheduled for vaccinations beginning Monday, Nov. 9 -- will be added to that priority group.

A health official told CTV News the decision is the result of many children coming down with the flu.

Montreal Children's closes clinics, deploys staff to ER

The Montreal Children's Hospital has temporarily closed some non-urgent out-patient clinics and its Pediatric Test Centre so that staff can deal with a crush of patients with mild flu symptoms.

The redeployment of staff follows a rare joint advisory from the Children's and Ste-Justine Hospital warning parents to stay away from ERs unless their children are very sick.

On Tuesday, the message from the Children's hospital was "don't call us, we'll call you."

"If a child's doctor's appointment has been cancelled, parents will receive a phone call to reschedule the appointment," the hospital said in a statement.

"If parents do not receive a phone call they can presume their appointment will take place as scheduled."

Parents are asked not to call the hospital to confirm their appointment since there are not enough people on staff available to take the calls.

Parents whose doctors have ordered blood tests are asked to have them done at their local CLSC instead of the hospital.

Vaccination lineups

People lined up eagerly on Tuesday at Allancroft Elementary School in Beaconsfield hours before doors opened.

The vaccination clinic was for health care workers only, but some brought their children with them just in case.

"I'm hoping they'll vaccinate him. I don't know if they will but if not I'll be back on Monday," said one parent.

Cynthia Desjardins, a nurse, was told that she could be vaccinated, but not her children.

"I'm very frustrated I waited here," she said.

Suzanne Turmel, executive director of the West Island Heath and Social Services Centre, said health officials are obligated to stick to the schedule.

"It's very hard to turn people away -- especially because you're dealing with people's fears and you want to give the vaccine," she said.