National Advisory Committee on Immunization is coming under fire after contradicting the advice Canadians have been receiving for weeks to take the first vaccine against COVID-19 that they’re offered.NACI said Monday that the Pfizer-BioNTech and Moderna vaccines are “preferred” and that Canadians should weigh the risks of waiting for one of them before deciding whether to take a more immediate jab of either of the other two approved for use in Canada.The Johnson & Johnson and AstraZeneca vaccines have been linked to a new and extremely rare blood-clotting syndrome.