Prince Edward Island has suspended use of the Oxford-AstraZeneca vaccine for those aged 18 to 29 who had appointments for shots in pharmacies.
Health officials said in a brief statement the appointments are on hold pending further information expected Monday from Health Canada and the National Advisory Committee on Immunization.
In early March, Denmark and other European countries suspended the use of the AstraZeneca vaccine after reports of blood clots in some people.
Norway and Sweden also have paused the use of the AstraZeneca vaccine.
Health Canada has reassured Canadians the Oxford-AstraZeneca vaccine is safe and effective.
Last week, the company reported preliminary results from a trial in the United States that appeared stronger, saying it was 79 percent effective against infection.
That report prompted the independent monitoring board overseeing the trial for the U.S. National Institutes of Health to accuse the company of reporting incomplete data to show a better result.