TORONTO -- Experts are reminding Canadians to get the first vaccine that is available to them as some, particularly those who received AstraZeneca as their first shot, turn down a Moderna jab in favour of its Pfizer-BioNTech counterpart. Dr. Dale Kalina, an infectious disease physician at Joseph Brant Hospital in Burlington, Ont., told CTVNews.ca that Moderna and Pfizer are "very similar" vaccines and Canadians shouldnât be hesitant to get one over the other. "I think there is always a push for people to be competitive about getting the best of a vaccine, or a car or whatever it may be and that's just something that's part of our society," Kalina said in a telephone interview on Tuesday.