摘要Objective:To investigate the trend of mortality by COVID-19 before and after the national vaccination program using joinpoint regression analysis from 19 February 2020 to 5 September 2022.Methods:In the present study,a joinpoint regression analysis of monthly collected data on confirmed deaths of COVID-19 in Iran from February 19,2020 to September 5,2022 was performed.Results:After national vaccination in Iran,the trend of new monthly deaths due to COVID-19 was decreasing.The percentage of monthly changes from the beginning of the pandemic to the 19th month was 6.62%(95%CI:1.1,12.4),which had an increasing trend.From the 19th month to the end of the 31st month,the mortality trend was decreasing,and the percentage of monthly changes was-20.05%(95%CI:-8.3,-30.3)(P=0.002).The average percentage of monthly changes was-5%with a 95%CI of(-10.5,0.9).Conclusions:Along with other health measures,such as quarantine,wearing a mask,hand washing,social distancing,etc.,national vaccination significantly reduces the mortality rate of COVID-19.