EDMONTON -- There are 19 cases of the COVID-19 variant at an Edmonton retirement home, Dr. Deena Hinshaw said Wednesday afternoon.

Churchill Manor in Edmonton has a total of 27 coronavirus infections between staff and residents.

"Local public health teams and the operator are taking this outbreak extremely seriously and working closely together to limit spread and protect everyone involved," said the chief medical officer of health shortly after she reported 402 cases and a positivity rate of 3.9 per cent.

Alberta has 4,649 active cases and 251 patients in hospital, including 48 in ICU.

Dr. Hinshaw also reported 12 new deaths increasing fatalities to 1,902 since last March.

ALTA. EXTENDS TIMELINE BETWEEN DOSES

As government and health officials hinted Tuesday, Hinshaw announced the province would extend the period between first and second vaccine doses to up to four months "with the goal of providing first doses to all Albertans as soon as possible."

READ MORE: Alberta poised to extend time between COVID-19 doses to up to 16 weeks

The chief medical officer of health said Canadian research shows the first dose of the Moderna or Pfizer vaccine gives about 80 per cent protection against COVID-19, "a huge boost in immunity."

Albertans who already have an appointment for a second dose, and people who book their final appointment before March 10, can still get it within 42 days.

"From March 10 going forward, people who book vaccinations will only be able to book their first appointment, and they will then receive a reminder at a later date to book a second dose," Hinshaw explained.

"This change will significantly increase how quickly we can all offer Albertans the protection of their first dose. The more people we can offer this protection to in the coming weeks and months, the more effective we will be in stopping spread."

Dr. Hinshaw said Alberta is working to confirm exactly how many doses of the newly approved AstraZeneca vaccine it would received and hopes to give an update soon.

Alberta Health Services has administered 20,000 doses of the vaccine in the last week, Hinshaw said, and a total of 255,283 since December.