RESUMEN
Background. Symptoms during acute COVID-19 can limit daily activities and delay return to work and school. Little is known about the association between SARS-CoV-2 burden in either the upper airway or plasma and the duration of COVID-19 symptoms. Methods. ACTIV-2/A5401 is a platform trial for COVID-19 treatments in nonhospitalized symptomatic adults enrolled within 10 days of symptom onset. We included participants randomized to placebo from August 2020 to July 2021. Participants self-reported severity of 13 symptoms daily from day 0 (baseline) to 28 as Absent 0, Mild 1, Moderate 2, Severe 3;total symptom score was calculated as the sum of all scores. Anterior nasal (AN) and plasma SARS-CoV-2 RNA levels at day 0 were measured with a quantitative qPCR assay. The relationship between day 0 RNA and time to symptom improvement or resolution (first of 2 consecutive days of all symptoms improved or resolved from day 0, respectively) was evaluated using proportional hazards regression adjusted for time from symptom onset. Time to resolution of distinct symptoms was also assessed. Results. Among 570 participants randomized to placebo, median age was 48 years, 51% were female, and median time since symptom onset at baseline was 6 days;7% had prior COVID-19 vaccination. At day 0, AN RNA was detectable in 80% with a median of 4.1 log10 copies/ml (n=533, quartiles: 1.7, 6.0) and plasma RNA was detectable in 19% (91/476). Detectable plasma RNA at day 0, but not AN RNA, was associated with more severe symptoms at day 0 (2.4-point higher mean total symptom score, P=0.001). Both high AN (>=6 vs < 2 log10 copies/ml, adjusted hazard ratio [aHR] 0.63, P=0.001) and detectable plasma RNA (aHR 0.74, P=0.03) at day 0 predicted delayed symptom improvement. High AN RNA at day 0 also predicted a delay in symptom resolution (aHR 0.59, P=0.001). Both high AN RNA and detectable plasma RNA levels predicted delays in the resolution of cough and shortness of breath. Detectable plasma RNA also predicted delayed body pain resolution.