An investigation of the effects of lockdowns and COVID-19 vaccinations in Ireland

Abstract. The COVID-19 pandemic resulted in many deaths and much upheaval worldwide. Public health responses to the pandemic differed greatly between countries. In 2023, as we emerge from the aftermath of the pandemic, it is now timely to assess the impact of specific public health response measures such as lockdowns and vaccinations. This assessment can help inform the development of evidence-based strategies for future public health responses in pandemic scenarios. We describe the implementation of a Bayesian Hierarchical Poisson Regression (BHPR) model to estimate the impact of pandemic response measures and vaccination on all-cause deaths, including COVID-19, in Ireland. We find that the implementation of lockdown measures and an appropriate vaccination timeline were effective in reducing the number of deaths in Ireland by, most likely, reducing the COVID- 19 mortality rate. We believe our approach could be used to assess the impact of pandemic response measures and vaccination in other countries as well where similar data is available.