The SARS-CoV-2 test scale-up in the USA: an analysis of the number of tests produced and used over time and their modelled impact on the COVID-19 pandemic

Background: Rapid, accessible, and accurate testing was paramount to an effective US COVID-19 response. Federal partners supported SARS-CoV-2 testing scale-up through an interagency-coordinated approach that focused on expanding supply chains, research and development, validation, and improving patient access. We aimed to provide an overview of the federal efforts to scale up the testing response and study the impact of scale-up.

Methods: In this descriptive analysis, we mapped federal partner activities and milestones using the US Government Testing and Diagnostics Working Group (TDWG) and participating agency and department data from Jan 1, 2020, to Dec 31, 2022. Tests produced (TDWG), reported test positivity (US Centers for Disease Control and Prevention [CDC]'s COVID-19 Electronic Laboratory Reporting system and the Federal Direct Report testing data), reported COVID-19 case counts (CDC), hospitalisations (Department of Health and Human Services Unified Hospital Data Surveillance System and the CDC's National Healthcare Safety Network), and deaths (CDC) were analysed over time. We then developed an agent-based model to evaluate the impact testing had on COVID-19 outcomes using different scenarios. The scenarios were (1) if efforts led to substantially fewer tests produced, (2) if scale-up was delayed, affecting test access, and (3) if efforts led to substantially more tests produced.

Findings: Approximately 6·7 billion SARS-CoV-2 tests, including over 1·5 billion laboratory-based, 1·9 billion point-of-care (POC), and 3·2 billion over-the-counter (OTC) tests, were produced, and approximately 2·7 billion tests were performed between Jan 1, 2020, and Dec 31, 2022. Testing capacity exhibited various expansion phases, with laboratory-based capacity growing from approximately 6 million tests per month in March, 2020 to approximately 34 million tests per month in July, 2020; POC increased to approximately 126 million tests per month by December, 2020, and OTC increased to approximately 986 million tests per month by February, 2022. Comparison between the baseline (actual) and delay-in-testing scenario suggests the increased testing capacity potentially saved upwards of 1·4 million lives and averted 7 million hospitalisations.

Interpretation: Our study suggests that early development, manufacturing, and distribution of tests had a great impact on reducing severe COVID-19 outcomes. These results highlight the importance of robust and rapid test development, production, and distribution when addressing future public health threats.

Funding: US Administration for Strategic Preparedness and Response and US Centers for Disease Control and Prevention.