Prime Minister Justin Trudeau says his doctor told him he should get a second shot of the Oxford-AstraZeneca vaccine.
He recently received his first dose and fielded the question as Canadians wonder about mixing doses.
Trudeau says that advice shouldn't be provided by politicians, and public health officials and scientists are looking into it.
Ontario announced a pause yesterday on using AstraZeneca for first shots due to an increased risk of a rare blood-clotting syndrome linked to the vaccine.
It says today that it is still determining when it will start administering second AstraZeneca shots and is also reviewing the possibility of using a different vaccine for the second dose.
There have been at least eight cases in Ontario of the rare blood clotting syndrome linked to the AstraZeneca shot out of more than 901,800 doses given in the province. None of the Ontario cases have been fatal.
The province also says it is developing a plan to vaccinate children aged 12 to 17 starting in June.
Ontario says half of the province's adults have now received at least one dose of a COVID-19 vaccine.