Figure 3. SARS-CoV-2 Viral Load in Nasopharyngeal Swab at COVID-19 Diagnosis by Trial, COVID-19 Severity, SARS-CoV-2 Variant, and Days Since COVID-19 Onset.

At the bottom of each panel, the number and percentage of participants with detectable viral load (>0 copies/mL) at diagnosis are provided. In panel C, colors indicate the highest level of World Health Organization designation: dark blue for the ancestral variant, red for variants of concern, light blue for variants of interest, and gray for those missing sequence. In panel D, COVID-19 onset was defined in each parent protocol: the date of first positive polymerase chain reaction (PCR) test (AstraZeneca), symptom onset (Janssen), the earlier of the 2 (Novavax), or the later of the 2 (Moderna). Thus, for Janssen and Moderna there were some PCR-positive tests prior to COVID-19 onset.