Provinces have worked with local municipal governments, hospital systems, family doctors and independently owned pharmacies to aid in part, or in full with vaccination rollout.

However, the deal collapsed due to strained Canada–China relations, and the federal government later announced commitments to purchase vaccines being produced by AstraZeneca, Moderna, Pfizer and Janssen.

In early 2021, both Pfizer–BioNTech and Moderna did not ship the agreed upon quantities of secured vaccines to Canada and other countries, due to manufacturing challenges.

This funding for "national medical research strategy to fight COVID-19" included "vaccine development, the production of treatments, and tracking of the virus.

[23] On May 6, 2020, the NRC reached an agreement with Chinese pharmaceutical company CanSino Biologics to conduct clinical trials for its COVID-19 vaccine candidate Ad5-nCoV at Dalhousie University in Nova Scotia.

"[23] With the CanSino deal falling through, and the VTF revising its recommendations based on clinical trial data from other countries, Minister of Public Services and Procurement Anita Anand announced on August 5, 2020, that the federal government had committed to purchasing doses of the Moderna and Pfizer–BioNTech vaccines.

[28][29] In November 2020, Conservative Party leader Erin O'Toole criticized the federal government for focusing too heavily on the CanSino agreement, arguing that he "would not have put all our eggs in the basket of China.

[31] On December 9, 2020, Health Canada authorized emergency use of the Pfizer–BioNTech COVID-19 vaccine under the Interim Order Respecting the Importation, Sale and Advertising of Drugs for Use in Relation to COVID-19.

[36] Because of the cold storage logistics, the initial doses were delivered to 14 distribution sites in the provinces, with none being sent to the Canadian territories since they could not properly store the vaccine.

The 14 original distribution sites are located in St. John's, Halifax, Charlottetown, Miramichi, Quebec City, Montreal, Ottawa, Toronto, Winnipeg, Regina, Edmonton, Calgary, and two in the Greater Vancouver area.

[43] Following VTF and TTF recommendations, the federal government announced investment in two biomanufacturing companies—Vancouver-based Precision NanoSystems Incorporated (PNI) and Markham, Ontario-based Edesa Biotech Inc.

The Public Health Agency of Canada established a committee to review proposals the following month, swiftly and unanimously choosing Raymond Chabot Grant Thornton to act as third party administrator.

"[57] Pfizer's new "locked in" delivery schedule includes 475,000 doses in February and 444,600 per week in March, according to the PHAC's vaccine distribution tracker.

[59] According to the same Times columnist, who had interviewed those involved in "vaccine development, epidemiology, infection control and medical supply chains", they all said it was not surprising that Canada's rollout was not happening as planned.

[65] After an agreement was reached with Pfizer to move up some deliveries, it was projected a total of 8 million vaccine doses (from three suppliers) will be available in Canada by the end of March 2021.

[79] However, Health Canada held the shipment for a safety review, citing production issues at the facilities of Emergent BioSolutions.

[100] On August 13, 2021, Minister of Intergovernmental Affairs Dominic LeBlanc and Transport Minister Omar Alghabra announced that the federal government plans to mandate the vaccination of all federal public servants, employees in federally-regulated transport industries, and passengers of commercial air travel, interprovincial rail service, and large marine vessels with overnight accommodations (e.g. cruise ships).

[109] On September 16, 2021, with the expiration of the aforementioned Interim Order, Health Canada officially granted full approval to the Moderna and Pfizer vaccines for individuals aged 12 and older.

[121] On April 5, 2022, NACI began recommending that fourth doses be given to vulnerable populations, namely seniors living in long-term care homes and people aged 80 and up.

[123][124] On September 1, 2022, Moderna's new bivalent vaccine, which targeted both the original strain of SARS-CoV-2 and the Omicron BA.1 variant, received authorization from Health Canada.

[128] On October 7, 2022, Pfizer's new bivalent vaccine, which targeted the original strain of SARS-CoV-2 as well as the Omicron BA.4 and BA.5 subvariants, was approved by Health Canada for individuals aged 12 years and up.

The rollout then progressed towards other vulnerable groups, including first responders, essential workers, and people with comorbidities, before opening up to the wider general public.

[138] Travellers over the age of 12 on all federally regulated modes of transportation (such as domestic and international flights departing from most airports in Canada, those riding on Via Rail and Rocky Mountaineer trains as well as cruise ships) were required to show proof of full vaccination against COVID-19 beginning October 30, 2021.

[140] Legal scholars also questioned the constitutionality of vaccine mandates, not only on the basis of individual exemptions, but also the extent of the impact that firing so many workers would have on the Canadian population at-large.

Alternatively, Si Wen Shen from the Université de Montréal Faculty of Law proposed the idea of provincial governments invoking Section 33 (notwithstanding clause) of the Canadian Charter of Rights and Freedoms in order to circumvent any legal challenges on constitutional grounds.

[141] Many private companies nationwide like Air Canada[142] and major accounting firms have mandated vaccination policies internally.

As of 2 December 2020[update] the Canadian government had invested over $1 billion,[203] including pre-placed orders for seven different vaccines, four of which are now authorized for use by Health Canada.

[237] On March 4, 2021, the National Advisory Committee on Immunization (NACI) recommended that a maximum of four months or 112 days could be achieved effectively between second doses.

[243] Health Canada accepted the relabelling of the product, however the revelation required the acquisition of millions of low dead space syringes in order to extract the last dose from the vial.

[256] Due to increased reports of post-vaccination embolic and thrombotic events, on May 11, 2021, the provinces of Alberta and Ontario decided to cease offering first dose appointments of the Oxford-AstraZeneca vaccine.