MONTREAL -- A COVID-19 vaccine likely won't be a requirement to return to the physical classroom at some universities in September, with several large schools saying they have no intention of mandating proof of immunization for students. Though some schools remain undecided, the decisions from the University of British Columbia, University of Alberta and McGill University come as governments around the world work out how to handle so-called vaccine passports. "There's quite a range of opinions," said Andrew Kirk, an engineering professor and head of the McGill Association of University Teachers. "We haven't taken a formal position." Some professors, he said, believe McGill should require that students be fully vaccinated before returning to laboratories and lecture halls.