evidence: Patients also self-reported COVID-19 vaccination status, including the number of doses (up to 4), product, and month and year of receipt for each dose. For doses received in the same month or the month prior to testing, an additional question was asked to specify whether the dose was received 14 days or more before testing. Vaccination reporting was not mandatory, and information was not verified. Data were reported to HHS with an estimated 3-day lag and were deidentified to remove any personally identifying information. [...] Because protection from mRNA COVID-19 vaccines is substantially lower in immunocompromised individuals18 and the recommended vaccine dosing regimen is different from that of immunocompetent individuals,19 tests from individuals reporting an immunocompromising condition were excluded. Tests from persons reporting a positive COVID-19 test result within the previous 90 days were excluded to reduce potential misclassification. Tests with unknown vaccination status or incomplete vaccination data (ie, missing vaccination dates or products), from individuals reporting prior receipt of 1 or 4 mRNA vaccine doses or of non-mRNA COVID-19 vaccines, or from persons with improbable ages (defined as >100 years) were also excluded.