Figure 4.

Reverse-transcriptase polymerase chain reaction (RT-PCR) and antigen-detection rapid diagnostic test (Ag-RDT) positivity by day past exposure (DPE). Filled lines represent RT-PCR results; dashed lines, Ag-RDT results; shaded regions, 95% confidence intervals. Exposure was defined as being within 6 feet of an infected person without a mask for ≥15 minutes over a 24-hour period. DPE 0 was defined as the first day of the reported exposure. The percent positivity for Ag-RDTs and RT-PCR tests by day past exposure is shown among all exposed participants (A), unvaccinated (black) and vaccinated individuals (green) (B), and asymptomatic (black) and symptomatic (green) participants (C). Percent positivity was defined as the number of participants with a positive test result (Ag-RDT or RT-PCR) on each DPE divided by the number who tested positive with RT-PCR at least once during the observation period (DPE 0 to 10) and recorded a test on that specific DPE.