OTTAWA—The National Advisory Committee on Immunization says it is standing by its emergency recommendation to extend the delivery of second doses of COVID-19 vaccines up to four months. NACI’s experts issued a recommendation in early March to extend the dosing interval from three or four weeks to as long as 16 weeks, because vaccine supplies were limited and they felt getting some protection to more people faster was needed. Its followup recommendation, based on further study of vaccine, NACI says they still believe that to be the case. “his helps to provide direct protection to the individual and those around them and may also help to prevent spread in the community,” said the report released Wednesday. The panel says it expects the administration of second doses won’t end up taking as long as four months based on Canada’s expected vaccine supply. The recommendation came just as regulators in Europe and …