At-Home Versus Onsite COVID-19 School-based Testing: A Randomized Noninferiority Trial.

OBJECTIVES: Equitable access to coronavirus 2019 (COVID-19) screening is important to reduce transmission and maintain in-person learning for middle school communities, particularly in disadvantaged schools. Rapid antigen testing, and at-home testing in particular, could offer substantial advantages over onsite testing from a school district's perspective, but it is unknown if engagement in at-home testing can be initiated and sustained. We hypothesized that an at-home COVID-19 school testing program would be noninferior to an onsite school COVID-19 testing program with regard to school participation rates and adherence to a weekly screening testing schedule. METHODS: We enrolled 3 middle schools within a large, predominantly Latinx-serving, independent school district into a noninferiority trial from October 2021 to March 2022. Two schools were randomized to onsite and 1 school to at-home COVID-19 testing programs. All students and staff were eligible to participate. RESULTS: Over the 21-week trial, at-home weekly screening testing participation rates were not inferior to onsite testing. Similarly, adherence to the weekly testing schedule was not inferior in the at-home arm. Participants in the at-home testing arm were able to test more consistently during and before returning from school breaks than those in the onsite arm. CONCLUSIONS: Results support the noninferiority of at-home testing versus onsite testing both in terms of participation in testing and adherence to weekly testing. Implementation of at-home COVID-19 screening testing should be part of schools' routine COVID-19 prevention efforts nationwide; however, adequate support is essential to ensure participation and persistence in regular at-home testing.

Development of an At-Home COVID-19 Test Results-Reporting System for a School District Primarily Serving Underrepresented Minority Groups, San Diego, CA, 2021-2022.

School-sponsored at-home COVID-19 testing benefits users, school administrators, and surveillance efforts, although reporting results remains challenging. Users require simple systems with tailored posttest guidance, and administrators need timely positive test information. We built a system to serve these needs and to collect data for our Rapid Acceleration of Diagnostics-Underserved Populations Return to School Program study in San Diego County, California, from October 2021 through January 2022. We describe this system and our participant outreach strategies and outline a replicable model for at-home results reporting. (Am J Public Health. 2022;112(S9):S883-S886. https://doi.org/10.2105/AJPH.2022.307073).

Baculovirus-Free SARS-CoV-2 Virus-like Particle Production in Insect Cells for Rapid Neutralization Assessment.

Virus-like particles (VLPs) resemble authentic virus while not containing any genomic information. Here, we present a fast and powerful method for the production of SARS-CoV-2 VLP in insect cells and the application of these VLPs to evaluate the inhibition capacity of monoclonal antibodies and sera of vaccinated donors. Our method avoids the baculovirus-based approaches commonly used in insect cells by employing direct plasmid transfection to co-express SARS-CoV-2 envelope, membrane, and spike protein that self-assemble into VLPs. After optimization of the expression plasmids and vector ratios, VLPs with an ~145 nm diameter and the typical "Corona" aura were obtained, as confirmed by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Fusion of the membrane protein to GFP allowed direct quantification of binding inhibition to angiotensin II-converting enzyme 2 (ACE2) on cells by therapeutic antibody candidates or sera from vaccinated individuals. Neither VLP purification nor fluorescent labeling by secondary antibodies are required to perform these flow cytometric assays.