On Monday, Ontario health officials confirmed that the province would pause administering AstraZeneca vaccines to those 55 years of age and under.
Ontario's chief medical officer of health, Dr. David Williams, said that the province is "pausing on the use [of the vaccines] at this time for those under 55."
To date, AstraZeneca has not yet been administered to residents under the age of 60 in Ontario, as it was previously being used in a pharmacy pilot program for those 60-64 years of age.
Williams says there should be "no concern for those who have received [the vaccine] so far."
According to Williams, the province is awaiting both Health Canada's evaluation as well as an update from the European Association's Pharmacovigilance Committee before considering administering the vaccine to those under 55.
Ontario isn't the only province halting AstraZeneca vaccines
Multiple provinces have announced that they will be pausing the use of AstraZeneca for younger residents.
PEI was the first province to make the call, followed by Quebec, Ontario, Manitoba and British Columbia.
On Monday, Canada's National Advisory Committee on Immunization (NACI) made an official recommendation against the use of the vaccines on those under 55 years of age, according to reports by CBC.