photo of Mehdi Ammi

SPPA Associate Professor Mehdi Ammi

New paper from SPPA Associate Professor and lead author, Mehdi Ammi looks at COVID-19 policies and outcomes such as deaths, hospitalizations and ICU admissions across Canada,  and the relationship between non-pharmaceutical interventions (NPIs) and COVID vaccine coverage. The study, which found varying experiences across provinces, suggests the interaction of NPIs and vaccine uptake was primarily benefiting high-risk populations and highlights the need to better understand the combined impacts of policy restrictions on vaccination uptake.

Mehdi Ammi, Zachary W. Desson, Maeva Z. Doumbia, Non-pharmaceutical interventions and vaccination during COVID-19 in Canada: Implications for COVID and non-COVID outcomes Health Policy and Technology, Volume 13, Issue 1, March 2024, 100801


  • Canadian provinces had different experiences of COVID-19 policies and outcomes.
  • Interaction of policy restriction and vaccination coverage is to be better understood.
  • Combined restriction and vaccination were more beneficial in the booster campaign.
  • Less stringent restrictions did not necessarily lead to better economic outcomes.


As a federal country where health prerogatives are primarily at the subnational level (provinces), Canada has implemented non-pharmaceutical interventions (NPIs) of differing stringency and attained varied COVID-19 vaccination coverage across the different vaccination campaigns. NPIs and vaccination may have thus interacted in different ways.

A mixed-methods design combining a regression analysis and a comparative case study. The regression analysis focuses on COVID-19 outcomes such as COVID-19 cases, deaths, hospitalizations, and admissions in intensive care units. The case study centers on three provinces and explores outcomes beyond COVID-19, such as spillover on the healthcare system and the economy.

While more stringent NPIs are associated with lower COVID outcomes, their interaction with vaccination coverage depends on the vaccination campaign. Increasing the vaccination coverage with more stringent NPIs was not associated with a decrease in COVID cases growth rate during the primary campaign (two-doses), however it was associated with a decrease in COVID hospitalizations during the booster campaign. For non-COVID outcomes, having less stringent restrictions and lower initial vaccination coverage did not help prevent longer wait times for healthcare nor higher initial unemployment.

The differing interaction between NPIs and vaccination coverage suggests that the interaction was more effective when the vaccine uptake was primarily from high-risk populations. Confirming this finding would require further detailed microdata analysis.

Read full paper…