Hamilton public health officials confirm to @CBCNews that Ontario's 2nd case of a patient with rare #VITT blood clots after the AstraZeneca #COVID19 vaccine has been identified in a patient who remains in hospital. That brings Canada's confirmed total up to 5. @CBCAlerts

"While these serious reactions remain extremely rare, there is a robust process in place to monitor for any adverse events and have taken steps to ensure that these events are identified and treated as quickly as possible," Hamilton's medical officer of health says in a statement

"All COVID-19 vaccines available in the province have been determined to be safe and effective by Health Canada, and have been shown to prevent serious illness, hospitalization and death," Dr. Elizabeth Richardson added.

To date there have been two cases reported in Ontario, and one each in Alberta, Quebec and New Brunswick — out of more than 1.1 million shots administered, four of which were reportedly recovering at home. The age ranges are from individuals in their mid 30s to late 60s.