No effect of remdesivir or betamethasone on upper respiratory tract SARS-CoV-2 RNA kinetics in hospitalised COVID-19 patients: a retrospective observational study

Abstract Background The viral kinetics of SARS-CoV-2 has been considered clinically important. While remdesivir and corticosteroids are recommended for COVID-19 patients requiring oxygen support, there is a limited number of published reports on viral kinetics in hospitalised patients with COVID-19 treated with remdesivir or corticosteroids. Methods We conducted a retrospective study by collecting longitudinal samples from the nasopharynx/throat of 123 hospitalised patients (median age 55 years, 74% male) with COVID-19, to evaluate the effects of remdesivir and corticosteroid treatment on viral RNA levels. The subjects were divided into four groups: those receiving remdesivir (n = 25), betamethasone (n = 41), both (n = 15), or neither (n = 42). Time to viral RNA clearance was analysed using Kaplan-Meier plots, categorical data were analysed using Fisher’s exact test, and Kruskal-Wallis for continuous data. Viral RNA decline rate was analysed using a mixed effect model. Results We found no significant difference in SARS-CoV-2 RNA decline rate or time to SARS-CoV-2 RNA clearance between the groups. Moreover, clinical status at baseline was not correlated with time to viral clearance. Conclusions Since SARS-CoV-2 RNA kinetics was not affected by treatment, repeated sampling from the upper respiratory tract cannot be used to evaluate treatment response.