Guidance on the prioritization of initial doses of COVID-19 vaccine(s)

In November 2020, NACI released comprehensive and evidence-informed Preliminary guidance on key populations for early COVID-19 immunization to inform planning for the efficient, effective, and equitable allocation of COVID-19 vaccine(s) once authorized for use in Canada when limited initial vaccine supply will necessitate the prioritization of immunization in some populations earlier than others. The key populations identified by NACI for early COVID-19 immunization include: those at high risk for severe illness and death, those most likely to transmit to those at high-risk and workers essential to COVID-19 response, essential services for the functioning of society, and those in living or working conditions with elevated risk for infection or disproportionate consequences, including Indigenous communities. NACI also recommends the integration of elements to guide ethical decision-making involving equity, feasibility, and acceptability considerations across all key populations. NACI’s preliminary guidance on key populations for early COVID-19 immunization is summarized in Figure 1 of its evidence-informed guidance document.
NACI noted in this recent guidance on key populations for early immunization that a sequential approach cannot be determined until vaccine characteristics, results of clinical trials, and the number of available doses are known. As additional information on these factors has become available, NACI is providing urgent guidance on the efficient and equitable prioritization of initial doses of COVID-19 vaccines, (further sequencing key populations identified in its recent guidance), to assist with planning for allocation of the first COVID-19 immunization programs.
NACI will continue to carefully monitor the evidence related to COVID-19 and COVID-19 vaccine(s) and will update recommendations as evidence evolves. NACI will conduct a comprehensive, transparent review of authorized COVID-19 vaccines, including evidence on efficacy and safety in clinical trial populations once available, and provide timely evidence-informed recommendations on the use of COVID-19 vaccines as soon as possible.
Under the Interim Order Respecting the Importation, Sale and Advertising of Drugs for Use in Relation to COVID-19. Health Canada could make regulatory decisions for COVID-19 vaccines that have completed Phase 3 clinical trials (i.e., Moderna and Pfizer/BioNTech) for potential authorized use in Canada very soon. Through advanced purchase agreements, Canada will initially receive a combined total of 6 million doses of the Moderna and Pfizer/BioNTech COVID-19 vaccines, if authorized, for distribution and allocation in the first quarter of 2021.
While complete or peer-reviewed evidence from Phase 3 clinical trials is not yet available, press releases by Pfizer/BioNtechFootnote1 and ModernaFootnote2 suggest favourable efficacy and safety of their COVID-19 vaccines. In their final analysis of 170 COVID-19 cases in a trial of 43,998 participants 12–85 years of age, Pfizer/BioNTech reported 95% efficacy 7 days after the second dose of their vaccine with 94% efficacy in adults 65 years of age and older. In their interim analysis of 95 COVID-19 cases in a trial of 30,000 participants 18 years of age and older, Moderna reported an efficacy of 94.5% 2 weeks after the second dose of their vaccine. Neither manufacturer reported serious safety concerns however, both reported that any adverse events were mainly transient and mild to moderate in severity.
NACI will not make specific recommendations on the clinical use of these COVID-19 vaccines until evidence from these Phase 3 clinical trials is available for committee review and synthesis according to NACI’s evidence-informed processFootnote3Footnote4.
NACI developed the following recommendations based on the evidence and extensive stakeholder consultations synthesized and presented in the NACI Preliminary guidance on key populations for early COVID-19 immunization, the most recent information available at the time of deliberation on vaccine supply, and preliminary information suggesting comparable efficacy and safety of the Moderna and Pfizer/BioNTech COVID-19 vaccines.