Investigating the Relationships Between COVID-19 Cases, Public Health Interventions, Vaccine Coverage, and Temperature in Ontario and Toronto

Objective : We examined the relationship between COVID-19 cases and Public Health Interventions (PHIs). We also explored the relationship between cases and vaccine, and temperature. We compared the results with published mathematical models. Methods : We developed monthly PHI scores using the Oxford COVID-19 Government Response Tracker for May 2020 to May 2021. We calculated PHI scores by summing the highest monthly score of each intervention and expressed the PHI score as a percentage of the maximum. We obtained vaccine coverage and temperature data from January 2021 to September 2023. We calculated Spearman’s rank-order correlation coefficients to examine correlations. Results : Correlation for cases and PHI was positive (r = 0.947, p <.0001). Correlation for cases and vaccine coverage was approximately zero (r = 0.0165, p = 0.957) for January 2021 to January 2022, and negative for February 2022 to September 2023 (r = -0.816, p <.0001). Correlation for cases and temperature was negative for January 2021 to January 2022 (r = -0.676, p = 0.0112), and almost zero for February 2022 to September 2023 (r = -0.162, p = 0.494). Models showed negative correlation for PHI and vaccine coverage, and mixed results for temperature. Conclusion : There was a positive correlation between cases and PHI. Prior to vaccine threshold coverage, there was no correlation for vaccination and negative correlation for temperature. Post vaccine threshold, there was a negative correlation for vaccination and no correlation for temperature. Correlation results for PHI and temperature differed from mathematical models.