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Open Forum Infectious Diseases ; 9(Supplement 2):S492, 2022.
Article in English | EMBASE | ID: covidwho-2189801


Background. Remdesivir (RDV) is a broad-spectrum nucleotide analog prodrug approved for the treatment of COVID-19 in non-hospitalized and hospitalized adult as well as pediatric patients with clinical benefit demonstrated in multiple Phase 3 trials. Here we present SARS-CoV-2 resistance analyses from the Phase 3 ACTT-1 placebo-controlled clinical trial in hospitalized adults. Methods. Oro- or nasopharyngeal swab samples in ACTT-1 study were collected on Day 1, 3, 5, 8, 11, 15, and 29. All participants with >80th and 50% of participants with < 20th percentile of cumulative viral shedding underwent resistance analysis in both the RDV and placebo arm. The SARS-CoV-2 genome was sequenced using next generation sequencing. Phenotyping was conducted using virus isolation from clinical samples or generation of select site-directed mutants (SDMs) in a SARS-CoV-2 replicon system. Results. The majority of the sequencing data were obtained from participants with 80th percentile of cumulative viral shedding from the RDV and placebo arms as shown in Table 1. Among participants with both baseline and postbaseline sequencing data, emergent substitutions in nsp12 were observed in 12 of 31 participants (38.7%) treated with RDV and 12 of 30 participants (40.0%) in the placebo arm. The nsp12 substitutions that emerged in the RDV arm were only observed in one participant each, and the majority were present as mixtures with wildtype sequence. The following nsp12 mutations emerged in the RDV treatment group and were successfully phenotyped as clinical isolates or SDMs with low to no fold change in RDV susceptibility: A16V (0.8-fold), P323L+V792I (2.2-fold), C799F (2.5-fold), K59N (1.0-fold), and K59N+V792I (3.4-fold). V792I and C799F were identified previously in vitro in resistance selection experiments (Stevens Sci Transl Med 2022). In addition, for D684N and V764L identified in the RDV arm, the recovery of neither clinical isolates nor SDMs for phenotypic analysis were successful. Conclusion. The similar rate of emerging nsp12 substitutions in participants treated with RDV compared to placebo and the minimal to no change in RDV susceptibility among the treatment-emergent nsp12 substitutions support a high barrier to RDV resistance development in COVID-19 patients.

Open Forum Infectious Diseases ; 9(Supplement 2):S33-S34, 2022.
Article in English | EMBASE | ID: covidwho-2189510


Background. ACTT-1 demonstrated clinical efficacy of remdesivir (RDV) in hospitalized patients with COVID-19;subgroup analyses suggested those most likely to benefit presented with milder clinical illness. To further clarify what subsets of hospitalized patients might benefit from RDV, we analyzed virological and immunological biomarkers in this previously reported cohort. Methods. Serum and upper respiratory tract (URT) swabs were collected on Day 1, 3, 5, 8, and 11 while hospitalized;Day 15 and 29 as able were collected and tested for quantitative RNA (URT and plasma), serum nucleoprotein (NPR), IL-6, CRP through Day 6, and serostatus (baseline only). Participants with a baseline and at least one subsequent sample were used in this analysis. Associations of all these biomarkers with clinical outcomes (mortality, recovery) and response to therapy were assessed. Of the 1062 participants in ACTT-1, 642 had baseline and at least one subsequent sample within 6 days of randomization (Fig 1, Table 1). Results. RDV-treated patients with moderate/severe disease who had elevated baseline NPR levels recovered faster (RRR 1.95 vs 1.04, p = 0.01);similar trends were noted for plasma and URT RNA levels (Fig 2A);mortality treatment effects by viral load subgroups (high or low) were not seen (Fig 2B). In patients with less severe illness, RDV treatment was associated with an accelerated decline in NPR (difference -0.062 log10 pg/ml per day, p = 0.003) and plasma RNA levels (difference -0.040 log10 pg/ml per day, p = 0.004. Fig 3A), and a decrease in the proportion of patients with increasing and/or persistent viral loads (Fig 3B). Patients with increasing/persistent viral loads also took longer to recover than those with decreasing viral loads, irrespective of disease severity: RRR for plasma RNA 0.45, 95% CI 0.28-0.73, RRR for NPR 0.44, 95% CI 0.22-0.88 for moderate/severe disease;RRR for plasma RNA 0.26, 95% CI 0.10 - 0.70 , RRR for NPR n.e. (no recoveries) for critical disease (Fig 4). Conclusion. Our study demonstrates a systemic antiviral effect of remdesivir, shows the prognostic value of viral and immunologic biomarkers for mortality and failure to recover, and identifies a group of hospitalized patients with COVID-19 most likely to benefit from remdesivir treatment. (Figure Presented).

Acs Es&T Water ; : 12, 2022.
Article in English | Web of Science | ID: covidwho-1927042


Wastewater based epidemiology (WBE) has emerged as a tool to track the spread of SARS-CoV-2. However, sampling at wastewater treatment plants (WWTPs) cannot identify transmission hotspots within a city. Here, we sought to understand the diurnal variations (24 h) in SARS-CoV-2 RNA titers at the m A neighborhood level, using pump stations that serve vulnerable communities (e.g., essential workers, more diverse communities). Hourly composite samples were collected from wastewater pump stations located in (i) a residential area and (ii) a shopping district. In the residential area, SARS-CoV-2 RNA concentration (N1, N2, and E assays) varied by up to 42-fold within a 24 h period. The highest viral load was observed between 5 and 7 am, when viral RNA was not diluted by stormwater. Normalizing peak concentrations during this time window with nutrient concentrations (N and P) enabled correcting for rainfall to connect sewage to clinical cases reported in the sewershed. Data from the shopping district pump station were inconsistent, probably due to the fluctuation of customers shopping at the mall. This work indicates pump stations serving the residential area offer a narrow time period of high signal intensity that could improve the sensitivity of WBE, and tracer compounds (N, P concentration) can be used to normalize SARS-CoV-2 signals during rainfall.