Abstract

Background Non-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.

Methods We 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.

Results The 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.

Conclusion In 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.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

Senior Talent Startup Fund of Nanchang University

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Data Availability

All data produced in the present study are available upon reasonable request to the authors.

List of abbreviationsNPIsNon-pharmaceutical interventionsCOVID-19Coronavirus disease 2019RtEffective reproductive numberR0Basic reproduction number