Real-world effectiveness of non-pharmaceutical interventions in containing COVID-19 pandemic after the roll-out of coronavirus vaccines: A systematic review

BackgroundNon-pharmaceutical interventions (NPIs) have been widely used to control the transmission of infectious diseases. However, the current research evidence on the policy mechanisms of NPIs is still limited. This study aims to systematically identify, describe, and evaluate the existing literature for the real-world effectiveness of NPIs in containing COVID-19 pandemic after the roll-out of coronavirus vaccines, in order to search for optimal strategies for implementing NPIs. MethodsWe conducted a comprehensive search of relevant studies from January 1, 2021, to June 4, 2023 in PubMed, Embase, Web of science and MedRxiv. Two authors independently assessed eligibility and extracted data. Risk of bias assessment tool was used to evaluate the study design, statistical methodology, and quality of reporting. Data were collected, synthesised and analyzed through quantitative and qualitative approaches. The findings were presented using summary tables and figures, including information on the target countries and regions of the study, types of NPIs, and evidence quality. ResultsThe review included a total of seventeen studies that examined the real-world effectiveness of NPIs in containing the COVID-19 pandemic after the vaccine roll-out. These studies used five composite indicator that combined multiple NPIs and fourteen individual NPIs. The studies had an average quality assessment score of 13 (range: 10-16), indicating moderately high quality. Among the included studies, nine assessed the effectiveness of the composite indicator, with four of them also evaluating individual NPIs. Additionally, twelve studies investigated the effectiveness of individual NPIs. The most frequently evaluated individual NPIs were testing policy, restrictions on gathering, facial covering, and school closure. Workplace closures and stay-at-home requirements were also assessed. The effectiveness of NPIs varied depending on time frames, countries and regions. ConclusionIn summary, the research evidence suggests that NPIs remain effective in curbing the spread of COVID-19 even after the roll-out of vaccines. Studies based on different contexts had different viewpoints or conclusions regarding the effectiveness of NPIs in containing the COVID-19 pandemic. Further research is needed to understand the policy mechanisms and address potential future challenges.