Background: Public health interventions are organised efforts made to improve health at a population level. Vaccine impact can be assessed by comparing the trends in a targeted disease before and after the introduction of the vaccine. The study aimed to analyse the trend in incidence and mortality of COVID-19 in Ireland from March 2020 to February 2022. Methods: The age-standardized COVID-19 incidence and mortality rates in Ireland were calculated by direct standardization using the European Union standard population. Monthly percentage change (MPC) and the corresponding 95% confidence interval (CI) was computed for the trends using the joinpoint regression analysis. The data was obtained from the Central Statistics Office and Health Protection and Surveillance Centre, Ireland. Results: The COVID-19 incident rate sustained an upward trend two years post-pandemic. The incidence rate increased by 1.5 % per month (p<0.05) for both the male and female populations. The mortality rate showed a rise and fall trend. Among the female, deaths from COVID-19 fell in the periods of March 2020 to July 2020 (MPC = -43.6%; 95% CI, -77.6 – 42.0); p = 0.197), January 2021 to June 2021 (MPC = -54.7%; 95% CI, -81.5 – 11.0; p = 0.077) and December 2021 to February 2022 (MPC = -1.4%; 95% CI, -98.1 – 4487.1; p = 0.994). For the males, COVID-19 deaths decreased in the periods of March 2020 to August 2020 (MPC = 33.3%; 95% CI, -72.5 – 62.0%; p = 0.333), February 2021 to June 2021 (MPC = -70.0%; 95% CI, -94.7 – 71.6; p = 0.155) and December 2021 to February 2022 (MPC = -0.4%; 95% CI, -77.4 – 339.0; p = 0.996). Conclusions: The finding suggests that COVID-19 vaccination has no impact on the transmission of SARS-CoV-2. The impact of the vaccines in preventing deaths from COVID-19 requires further research.