Could COVID-19 Mask and Vaccine Mandates Have Made a Difference if They Were Rolled Out Earlier?
摘要
Hospitalisations and deaths due to COVID-19 in Canada declined after the first wave, thanks to nonpharmaceutical interventions and the vaccination campaign starting in December 2020, despite the emergence of highly contagious variants. We used an age-structured extended susceptible-exposed-infected-recovered compartment model to mimic the transmission of COVID-19 in Ontario from March 1, 2020, to May 31, 2021. We examined several counterfactual scenarios: (1) no mask mandates, (2) no vaccination, (3) instigating the mask mandate a month earlier and (4) rolling out the vaccine a month earlier. A 1-month-earlier vaccination program could have significantly decreased the number of cases and hospitalisations, but 1-month-earlier mask mandates would not have. It follows that the mandates that were implemented in practice were not optimal, but mostly performed well. Our model demonstrates that mask mandates played a vital role in saving lives in the first wave of the COVID-19 outbreak and that the vaccination programme was crucial to averting subsequent cases and hospitalisations after it was implemented.