JMIR Publications

ABSTRACT

Background:

This study provides an update to the status of the COVID-19 pandemic in Canada building upon our initial analysis conducted in 2020 by incorporating an additional two years of data.

Objective:

First, we aim to summarize the status of the pandemic in Canada when the World Health Organization (WHO) declared the end of the public health emergency for the COVID-19 pandemic on May 5, 2023. Second, we use dynamic and genomic surveillance methods to describe the history of the pandemic in Canada and situate the window of the WHO declaration within the broader history. Third, we aim to provide historical context for the course of the pandemic in Canada.

Methods:

In addition to updates of traditional surveillance data and dynamic panel estimates from the original study Post et al. (2021), this study used data on sequenced SARS-CoV-2 variants from the Global Initiative on Sharing All Influenza Data (GISAID) to identify the appearance and duration of variants of concern. We used Nextclade nomenclature to collect clade designations from sequences and Pangolin nomenclature for lineage designations of SARS-CoV-2. Finally, we conducted a one-sided t-test for whether provincial and territorial weekly speed was greater than an outbreak threshold of ten. We ran the test iteratively with six months of data across the sample period.

Results:

Canada’s speed remained below the outbreak threshold for eight months by the time of the WHO declaration ending the COVID-19 emergency of international concern. Acceleration and jerk were also low and stable. While the 1-day persistence coefficient remained statistically significant and positive (1.074), the 7-day coefficient was negative and small in magnitude (-0.080). Furthermore, shift parameters for either of the two most recent weeks around May 5, 2023, were negligible, meaning the clustering effect of new COVID-19 cases had remained stable in the two weeks around the WHO declaration. From December of 2021 onward, Omicron was the predominant variant of concern in sequenced viral samples. The rolling t-test of speed equal to ten became entirely insignificant from mid-October 2022 onward.

Conclusions:

While COVID-19 continues to circulate in Canada, the rate of transmission remained well below the threshold of an outbreak for eight months ahead of the WHO declaration. COVID-19 is endemic in Canada and no longer reaches the threshold of an outbreak definition. Both standard and enhanced surveillance metrics confirm that the pandemic had ended in Canada by the time of the WHO declaration.