OTTAWA—Canada’s national panel of vaccine experts says a worsening pandemic and limited supplies of COVID-19 vaccines are good enough reasons to temporarily delay giving a second dose but would prefer the planned schedule is followed whenever possible. The two COVID-19 vaccines approved for use in Canada both require two doses, with Pfizer and BioNTech’s vaccine label requiring two doses given 21 days apart, and Moderna’s needing two doses 28 days apart. In new recommendations issued late Tuesday, the National Advisory Committee on Immunization, or NACI, said every effort should be made to follow those dosing schedules. However, it notes there can be exceptions, particularly when vaccine supplies are so hard to come by and the spread of the virus in a given jurisdiction is rapid. “Model-based studies suggest population health benefits may be greater with a more balanced approach that does not withhold doses during early distribution in order to …