EDMONTON -- Alberta joined other provinces Monday in pausing its use of the the AstraZeneca COVID-19 vaccine for those under the age of 55.

Dr. Deena Hinshaw, the province's chief medical officer of health, says the province "may still be able" to hit its end of June target to vaccinate every adult Albertan.

"This is a precautionary measure that is being taken across Canada," she said. "This pause will allow Health Canada to conduct further assessments and gather more information from around the world."

Canada's National Advisory Committee on Immunization has recommended that it not be given to people under the age of 55.

That comes after more reports that patients in Europe developed blood clots following vaccination with the AstraZeneca product.

Dr. Hinshaw says about 900 Albertans under the age of 55 have already had the shot. None had received a second dose.

"These individuals are not at high risk of blood clots," she said. "We are pausing to get more information."

The shot will continue to be given to those over the age of 55.

Several provinces have also announced plans to restrict the use of the vaccine.

Prince Edward Island was first out of the gate Monday morning, saying it will no longer give the AstraZeneca vaccine to anyone between the ages of 18 and 29.

British Columbia, Manitoba and Quebec announced later in the day that they were halting vaccinations using AstraZeneca doses for anyone under the age of 55.

Despite the pause, Dr. Hinshaw says the vaccine is still useful for many Albertans.

"The benefits of getting the vaccine far outweigh the small potential risk in groups more likely to have severe outcomes from COVID-19 infections."

She also noted there were "no safety signals" with the other vaccines being used in Alberta.

545 NEW CASES

Dr. Hinshaw wasn't scheduled to give an in-person update until Tuesday, but spoke early Monday afternoon and shared partial COVID-19 data. 

Alberta reported 545 new cases, including 249 new variant cases. 

There are 288 Albertans in hospital being treated for COVID-19 including 64 in intensive care units. 

About 8,300 tests were administered with a positivity rate of 6.5 per cent. 

Alberta reported no new deaths on Monday. 

More detailed data will be made available on the province's interactive app later Monday afternoon.

VACCINATIONS RAMP UP

While cases continue to grow, so do the number of vaccinations. 

On Monday, the province entered Phase2B of its vaccination rollout, meaning about a million Albertans can book an appointment starting tomorrow.

On March 30, those born 1957-63 will be able to make an appointment in a pharmacy in Edmonton, Red Deer and Calgary.

Appointments will continue to open up by birth year. More than 608,000 doses of COVID-19 vaccines have been administered in Alberta as of March 27 including nearly 95,000 second doses.

Just over 11 per cent of the province's population has now received at least one dose.