Globally, COVID-19 has affected how children learn. We evaluated the impact of Test to Stay (TTS) on secondary and tertiary transmission of SARS-CoV-2 and potential impact on in-person learning in four school districts in the United States from September 13–November 19, 2021.


Implementation of TTS varied across school districts. Data on index cases, school-based close contacts, TTS participation, and testing results were obtained from four school districts in diverse geographic regions. Descriptive statistics, secondary and tertiary attack risk, and a theoretical estimate of impact on in-person learning were calculated.


Fifty-one schools in four school districts reported 374 COVID-19 index cases and 2,520 school-based close contacts eligible for TTS. The proportion participating in TTS ranged from 22%–79%. By district, the secondary attack risk (SAR) and tertiary attack risk (TAR) among TTS participants ranged between 2.2%–11.1% and 0%–17.6%, respectively. Nine clusters were identified among secondary cases and two among tertiary cases. The theoretical maximum number of days of in-person learning saved by using TTS was 976–4,650 days across jurisdictions.


TTS preserves in-person learning days. Decisions to participate in TTS may have been influenced by ease of access to testing, communication between schools and families, testing logistics, and school resources. TAR determination became more complicated when numbers of close contacts increased. Minimizing exposure through continued implementation of layered prevention strategies is imperative. To ensure adequate resources for implementation of TTS, community transmission levels should be considered.

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Competing Interests

CONFLICT OF INTEREST DISCLOSURES: The authors have no conflicts of interest relevant to this article to disclose.