OTTAWA—Canada is scheduled to receive a flood of new COVID-19 vaccine doses this week, with around 3.3 million shots due for delivery from different pharmaceutical companies over the coming days. The expected influx would mark the single-largest week of deliveries into Canada since the start of the pandemic, thanks to planned shipments from three different sources. The Public Health Agency of Canada says Pfizer and BioNTech are scheduled to ship nearly 1.2 million doses this week, as the two companies continue pumping out shots at a rapid pace. The federal government is also expecting around 1.5 million doses of the Oxford-AstraZeneca vaccine from the United States on Tuesday, which will arrive by truck and represent the first to come from south of the border. Canada’s vaccines to date have all come from Europe, with the exception of 500,000 AstraZeneca doses from India earlier this month. The government also says Moderna …