ABSTRACT
Monoclonal antibodies (mAbs) are the treatment of choice for high-risk ambulatory persons with mild to moderate COVID-19. We studied viral culture dynamics post-treatment in a subset of participants receiving the mAb bamlanivimab in the ACTIV-2 trial. Viral load by qPCR and viral culture were performed from anterior nasal swabs collected on study days 0 (day of treatment), 1, 2, 3, and 7. Treatment with mAb resulted in rapid clearance of culturable virus in participants without treatment-emergent resistance. One day after treatment, 0 of 28 (0%) participants receiving mAb and 16 of 39 (41%) receiving placebo still had culturable virus (p <0.0001); nasal viral loads were only modestly lower in the mAb-treated group at days 2 and 3. Recrudescence of culturable virus was detected in three participants with emerging mAb resistance and viral load rebound. The rapid reduction in shedding of viable SARS-CoV-2 after mAb treatment highlights the potential role of mAbs in preventing disease transmission.
ABSTRACT
The COVID-19 pandemic is complicated by cases of vaccine-breakthrough, re-infection, and widespread transmission of variants of concern (VOC). Consequently, the need to interpret longitudinal positive SARS-CoV-2 (SCV-2) tests is crucial in guiding clinical decisions regarding infection control precautions and treatment. Although quantitative tests are not routinely used diagnostically, standard diagnostic RT-PCR tests yield Ct values that are inversely correlated with RNA quantity. In this study, we performed a retrospective review of 72,217 SCV-2 PCR positive tests and identified 264 patients with longitudinal positivity prior to vaccination and VOC circulation. Patients with longitudinal positivity fell into two categories: short-term (207, 78%) or prolonged (57, 22%) positivity, defined as <= 28 (range 1-28, median 16) days and >28 (range 29-152, median 41) days, respectively. In general, Ct values declined over time in both groups; however, 11 short-term positive patients had greater amounts of RNA detected at their terminal test compared to the first positive, and 5 patients had RNA detected at Ct < 35 at least 40 days after initial infection. Oscillating positive and negative results occurred in both groups, although oscillation was seen three times more frequently in prolonged-positive patients. Patients with prolonged positivity had diverse clinical characteristics but were often critically ill and were discharged to high-level care or deceased (22%). Overall, this study demonstrates that caution must be emphasized when interpreting Ct values as a proxy for infectivity, predictor of severity, or a guide for patient care decisions in the absence of additional clinical context.
ABSTRACT
BackgroundEasily distributed oral antivirals are urgently needed to treat coronavirus disease-2019 (COVID-19), prevent progression to severe illness, and block transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report the results of a Phase 2a trial evaluating the safety, tolerability, and antiviral efficacy of molnupiravir in the treatment of COVID-19 (ClinicalTrials.gov NCT04405570). MethodsEligible participants included outpatients with confirmed SARS-CoV-2 infection and symptom onset within 7 days. Participants were randomized 1:1 to 200 mg molnupiravir or placebo, or 3:1 to molnupiravir (400 or 800 mg) or placebo, twice-daily for 5 days. Antiviral activity was assessed as time to undetectable levels of viral RNA by reverse transcriptase polymerase chain reaction and time to elimination of infectious virus isolation from nasopharyngeal swabs. ResultsAmong 202 treated participants, virus isolation was significantly lower in participants receiving 800 mg molnupiravir (1.9%) versus placebo (16.7%) at Day 3 (p = 0.02). At Day 5, virus was not isolated from any participants receiving 400 or 800 mg molnupiravir, versus 11.1% of those receiving placebo (p = 0.03). Time to viral RNA clearance was decreased and a greater proportion overall achieved clearance in participants administered 800 mg molnupiravir versus placebo (p = 0.01). Molnupiravir was generally well tolerated, with similar numbers of adverse events across all groups. ConclusionsMolnupiravir is the first oral, direct-acting antiviral shown to be highly effective at reducing nasopharyngeal SARS-CoV-2 infectious virus and viral RNA and has a favorable safety and tolerability profile.
ABSTRACT
BackgroundWhile SARS-CoV-2 infectious virus isolation in outpatients with COVID-19 has been associated with viral RNA levels and symptom duration, little is known about the host, disease and viral determinants of infectious virus detection. MethodsCOVID-19 adult outpatients were enrolled within 7 days of symptom onset. Clinical symptoms were recorded via patient diary. Nasopharyngeal swabs were collected to quantitate SARS-CoV-2 RNA by reverse transcriptase polymerase chain reaction and for infectious virus isolation in Vero E6-cells. SARS-CoV-2 antibodies were measured in serum using a validated ELISA assay. ResultsAmong 204 participants with mild-to-moderate symptomatic COVID19, the median nasopharyngeal viral RNA was 6.5 (IQR 4.7-7.6 log10 copies/mL), and 26% had detectable SARS-CoV-2 antibodies (IgA, IgM, IgG, and/or total Ig) at baseline. Infectious virus was recovered in 7% of participants with SARS-CoV-2 antibodies compared to 58% of participants without antibodies (probability ratio (PR)=0.12, 95% CI: 0.04, 0.36; p=0.00016). Infectious virus isolation was also associated with higher levels of viral RNA (mean RNA difference +2.6 log10, 95% CI: 2.2, 3.0; p<0.0001) and fewer days since symptom onset (PR=0.79, 95% CI: 0.71, 0.88 per day; p<0.0001). ConclusionsThe presence of SARS-CoV-2 antibodies is strongly associated with clearance of infectious virus isolation. Seropositivity and viral RNA levels are likely more reliable markers of infectious virus clearance than subjective measure of COVID-19 symptom duration. Virus-targeted treatment and prevention strategies should be administered as early as possible and ideally before seroconversion. ClinicalTrials.gov IdentifierNCT04405570 Key Points (Summary)Among COVID-19 outpatients within 7 days of symptom onset, the presence of SARS-CoV-2-specific antibodies was strongly associated with clearance of infectious virus. Seropositivity appears to be more reliable marker of infectious virus clearance than subjective measure of COVID-19 symptoms.
ABSTRACT
We describe early outcomes in 11 COVID-19 patients treated with the IL-6 receptor inhibitor tocilizumab. While C-reactive protein decreased, neither clinical improvement nor reduced temperature or oxygen requirements was observed in most patients. Our findings contrast with prior reports and raise questions about tocilizumab use in severe COVID-19.
