Background: Upon SARS-CoV-2 infection, most individuals develop neutralizing antibodies and T-cell immunity. However, some individuals reportedly remain SARS-CoV-2 PCR positive by pharyngeal swabs weeks after recovery. Whether viral RNA in these persistent carriers is contagious and stimulates SARS-CoV-2-specific immune responses is unknown. Methods: This cohort study was conducted between April 3 rd ÀJuly 9 th 2020, recruiting COVID-19 recovered individuals that were symptom-free for at least 14 days. We collected serum for SARS-CoV-2-specific total Ig, IgA and IgM detection by ELISA, pharyngeal swabs (two time points) for ddPCR and PBMCs for anti-SARS-CoV-2 CD8 T-cell dextramer analyses. Findings: We enrolled 203 post-symptomatic participants with a previous RT-PCR-verified SARS-CoV-2 infection. At time point 1, a median of 23 days (range 15À44) after recovery, 26 individuals (12Á8%) were PCR positive. At time point 2, 90 days (median, range 85À105) after recovery, 5 (5Á3%) were positive. There was no difference in SARS-CoV-2 antibody levels between the PCR negative and positive group. The persistent PCR positive group however, had SARS-CoV-2-specific CD8 T-cell responses of significantly increased breadth and magnitude. Assisted contact tracing among persistent PCR positive individuals revealed zero new COVID-19 diagnoses among 757 close contacts. Interpretation: Persistent pharyngeal SARS-CoV-2 PCR positivity in post-symptomatic individuals is associated with elevated cellular immune responses and thus, the viral RNA may represent replicating virus. However, transmission to close contacts was not observed indicating that persistent PCR positive individuals are not contagious at the post-symptomatic stage of the infection.
Background: The trans-membrane protease serine 2 (TMPRSS2) is essential for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cell entry and infection. Efficacy and safety of TMPRSS2 inhibitors in patients with coronavirus disease 2019 (Covid-19) have not been evaluated in randomized trials. Methods: We conducted an investigator-initiated, double-blind, randomized, placebo-controlled multicenter trial in patients hospitalized with confirmed SARS-CoV-2 infection from April 4, to December 31, 2020. Within 48 h of admission, participants were randomly assigned in a 2:1 ratio to receive the TMPRSS2 inhibitor camostat mesilate 200 mg three times daily for 5 days or placebo. The primary outcome was time to discharge or clinical improvement measured as 2 points improvement on a 7-point ordinal scale. Other outcomes included 30-day mortality, safety and change in oropharyngeal viral load.
SARS-CoV-2 is a new coronavirus with epicentre in the Hubei-region in China from where it spread globally in late 2019. 1-3 As of 11 March 2020, WHO declared the situation a pandemic. 4 Infection with SARS-CoV-2 leads to COVID-19, a disease ranging from mild respiratory illness to fatal pneumonia with acute respiratory distress syndrome (ARDS). 2,5 SARS-CoV-2 has proven highly contagious and has put an immense strain on healthcare systems worldwide.
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