Changes In Viral Load Research Articles

The impact of psoriasis biologic therapy on HIV viral load andCD4+ cell counts in HIV-positive individuals: A real-world cohort study.

Psoriasis is a chronic immune-mediated inflammatory disorder that also occurs in the setting of human immunodeficiency virus (HIV). Biological therapy has transformed the treatment landscape for psoriasis; however, individuals with HIV are excluded from clinical trials. The impact of biological therapy on blood parameters in HIV is unclear and is only observed in small case series. The aim of this study was to assess the effect of biological therapy in psoriasis vulgaris in individuals with well-controlled HIV on CD4+ cell counts, CD4+ proportion and HIV viral load over 12 months. This retrospective cohort study was conducted at a tertiary referral centre in Sydney, Australia and included 36 HIV-positive individuals with psoriasis treated with biological therapy, compared with 144 age-, gender- and HAART-matched individuals without psoriasis seen between 2010 and 2022. Outcomes of interest included HIV viral load, CD4+ cell count and incidence of infections. No statistically significant difference was seen in baseline HIV viral load and CD4+ count between individuals with and without psoriasis. No significant change in CD4+ count or HIV viral load was seen over the 12-month period of analysis in the HIV cohort without psoriasis. The HIV cohort treated with biological therapy for psoriasis also did not demonstrate any significant change in HIV viral load and CD4+ counts over the 12-month period examined. Stratification by type of biological therapy used did not identify any significant changes in these parameters. Rates of infections and adverse events were also not significantly different between cohorts. It is possible that minor blips seen in the biologics cohort may be a risk factor for future virological failure, and future prospective longitudinal studies are required. In individuals with well-controlled HIV, the use of biological therapy for psoriasis does not significantly impact HIV viral load, CD4+ cell count, CD4+ proportion and rates of infection over the first 12 months of therapy.

Cost of improved test and treat strategies in Indonesia.

To estimate and compare the cost of improved test and treat strategies in Indonesia under HIV Awal (Early) Testing and Treatment Indonesia (HATI) implementation trial in community-based and hospital-based clinics. The cost and outcome [i.e. CD4 + cell count] and viral load (VL) at the beginning of interventions and their change overtime) analysis of Simplifying ART Initiation (SAI), Community-based Organization and community-based ART Service (CBO), Motivational Interviewing (MI), Oral Fluid-based Testing (OFT), and Short Message Service (SMS) reminder in community-based and hospital-based clinics in 2018-2019. We estimated the total and unit costs per patient (under HATI implementation trial interventions) per year from societal perspective in various settings, including costs from patients' perspective for SAI and MI. We also analyzed the outcome variables (i.e. CD4 + cell count and VL at the beginning of each intervention, the change in CD4 + cell count and VL over time, and adherence rate). The unit cost per patient per year of SAI and SMS were lower at the community-based clinics, and more patients visited community-based clinics. The cost per patient visit from patient perspective for SAI and MI was mostly lower than 10% of the patients' household monthly expenditure. Average CD4 + cell count was higher and average VL was lower at the start of interventions at the community-based clinics, while average CD4 + cell count and VL changes and adherence rate were similar between the two types of clinics. Community-based clinics hold the potential for scaling up the interventions as it costs less from societal perspective and showed better outcome improvement during the HATI implementation trial.

A wastewater-based risk index for SARS-CoV-2 infections among three cities on the Canadian Prairie

Wastewater surveillance (WWS) is useful to better understand the spreading of coronavirus disease 2019 (COVID-19) in communities, which can help design and implement suitable mitigation measures. The main objective of this study was to develop the Wastewater Viral Load Risk Index (WWVLRI) for three Saskatchewan cities to offer a simple metric to interpret WWS. The index was developed by considering relationships between reproduction number, clinical data, daily per capita concentrations of virus particles in wastewater, and weekly viral load change rate. Trends of daily per capita concentrations of SARS-CoV-2 in wastewater for Saskatoon, Prince Albert, and North Battleford were similar during the pandemic, suggesting that per capita viral load can be useful to quantitatively compare wastewater signals among cities and develop an effective and comprehensible WWVLRI. The effective reproduction number (Rt) and the daily per capita efficiency adjusted viral load thresholds of 85 × 106 and 200 × 106 N2 gene counts (gc)/population day (pd) were determined. These values with rates of change were used to categorize the potential for COVID-19 outbreaks and subsequent declines. The weekly average was considered ‘low risk’ when the per capita viral load was 85 × 106 N2 gc/pd. A ‘medium risk’ occurs when the per capita copies were between 85 × 106 and 200 × 106 N2 gc/pd. with a rate of change <100 %. The start of an outbreak is indicated by a ‘medium-high’ risk classification when the week-over-week rate of change was >100 %, and the absolute magnitude of concentrations of viral particles was >85 × 106 N2 gc/pd. Lastly, a ‘high risk’ occurs when the viral load exceeds 200 × 106 N2 gc/pd. This methodology provides a valuable resource for decision-makers and health authorities, specifically given the limitation of COVID-19 surveillance based on clinical data.

Peginterferon lambda for the treatment of hospitalized patients with mild COVID-19: A pilot phase 2 randomized placebo-controlled trial.

This study aimed to investigate the efficacy and safety of subcutaneous injection of peginterferon lambda in patients hospitalized with COVID-19. In this study (NCT04343976), patients admitted to hospital with COVID-19 confirmed by RT-PCR from nasopharyngeal swab were randomly assigned within 48 h to receive peginterferon lambda or placebo in a 1:1 ratio. Participants were subcutaneously injected with a peginterferon lambda or saline placebo at baseline and day 7 and were followed up until day 14. We enrolled 14 participants; 6 participants (85.7%) in the peginterferon lambda group and 1 participant (14.3%) in the placebo group were treated with remdesivir prior to enrollment. Fifty percent of participants were SARS-CoV-2 RNA negative at baseline although they tested SARS-CoV-2 RNA positive within 48 h of randomization. Among participants who were SARS-CoV-2 positive at baseline, 2 out of 5 participants (40%) in the peginterferon lambda group became negative at day 14, while 0 out of 2 participants (0%) in the placebo group achieved negativity for SARS-CoV-2 by day 14 (p > 0.05). The median change in viral load (log copies per ml) was +1.72 (IQR -2.78 to 3.19) in the placebo group and -2.22 (IQR -3.24 to 0.55) in the peginterferon lambda group at day 14 (p = 0.24). Symptomatic changes did not differ between the two groups. Peginterferon lambda was well tolerated with a few treatment-related adverse effects. Peginterferon lambda appears to accelerate SARS-CoV-2 viral load decline and improve plasma disease progression markers in hospitalized patients with COVID-19.

Cherax quadricarinatus Resistant to Chequa iflavirus: A Pilot Study.

High mortalities of redclaw crayfish (Cherax quadricarinatus) were reported from northern Queensland farms, mainly attributed to two viruses, Chequa iflavirus and Athtab bunyavirus. From a research population of redclaw crayfish with these pre-existing viral infections, five individuals were found uninfected by Chequa iflavirus but infected with Athtab bunyavirus. A pilot study was designed to examine if progeny crayfish from this cohort were resistant to infections by Chequa iflavirus. Two experiments measured changes in viral load with RT-qPCR. Seven donors, four negative controls and six crayfish injected with a purified virus or saline were used. In Experiment 1, the purified viral inoculum was injected into the crayfish, and they were bled 14 days post-injection (dpi). In Experiment 2, haemolymph containing the viruses was injected into the same crayfish and they were bled at 24 hpi, 48 hpi, 7 dpi and 14 dpi. In Exp. 1, the crayfish cleared Chequa iflavirus infections within 14 dpi, while in Exp. 2, it was within 24 hpi. One mortality was observed, but that crayfish had cleared the virus before dying. The number of copies of Athtab bunyavirus and the weights of the crayfish did not differ significantly (p > 0.05) between the control and injected crayfish. Histology of crayfish all showed that the haemolymph vessels were clear of granulomas, suggesting no bacterial involvement. There was no melanisation in the gill tissue of control crayfish, but it was prominent in virus-injected crayfish. Neither group had haemocytic infiltration of the muscle fibres. Anti-viral immune mechanisms of RNA interference and Cherax quadricarinatus Down Syndrome Cell Adhesion Molecule (DSCAM) are hypothesised to be involved in viral clearance. We conclude that these crayfish were resistant to Chequa iflavirus infections and could be commercially exploited by aquaculturists as a nuclear breeding stock if numbers are increased over time.

T cell immunity ameliorates COVID-19 disease severity and provides post-exposure prophylaxis after peptide-vaccination, in Syrian hamsters.

The emergence of novel SARS-CoV-2 variants that resist neutralizing antibodies drew the attention to cellular immunity and calls for the development of alternative vaccination strategies to combat the pandemic. Here, we have assessed the kinetics of T cell responses and protective efficacy against severe COVID-19 in pre- and post-exposure settings, elicited by PolyPEPI-SCoV-2, a peptide based T cell vaccine. 75 Syrian hamsters were immunized subcutaneously with PolyPEPI-SCoV-2 on D0 and D14. On D42, hamsters were intranasally challenged with 102 TCID50 of the virus. To analyze immunogenicity by IFN-γ ELISPOT and antibody secretion, lymphoid tissues were collected both before (D0, D14, D28, D42) and after challenge (D44, D46, D49). To measure vaccine efficacy, lung tissue, throat swabs and nasal turbinate samples were assessed for viral load and histopathological changes. Further, body weight was monitored on D0, D28, D42 and every day after challenge. The vaccine induced robust activation of T cells against all SARS-CoV-2 structural proteins that were rapidly boosted after virus challenge compared to control animals (~4-fold, p<0.05). A single dose of PolyPEPI-SCoV-2 administered one day after challenge also resulted in elevated T cell response (p<0.01). The vaccination did not induce virus-specific antibodies and viral load reduction. Still, peptide vaccination significantly reduced body weight loss (p<0.001), relative lung weight (p<0.05) and lung lesions (p<0.05), in both settings. Our study provides first proof of concept data on the contribution of T cell immunity on disease course and provide rationale for the use of T cell-based peptide vaccines against both novel SARS-CoV-2 variants and supports post-exposure prophylaxis as alternative vaccination strategy against COVID-19.

SARS-CoV-2 neutralizing antibody therapies: an early retrospective cohort study of 26 hospitalized patients treated with bamlanivimab or casirivimab/imdevimab

ObjectivesIn this early retrospective cohort study, a total of 26 patients with SARS-CoV-2 were treated with bamlanivimab or casirivimab/imdevimab, and the reduction of the viral load associated with the developed clinical symptoms was analyzed. MethodsPatients in the intervention groups received bamlanivimab or casirivimab/imdevimab. Patients without treatment served as control. Outcomes were assessed by clinical symptoms and change in log viral load from baseline based on the cycle threshold over a period of 18 days. ResultsMedian log viral load decline was higher in both intervention groups after 3 and 6 days compared to control. However, at later time points, the decline of the viral load was more distinct in the control group. Mild symptoms of COVID-19 were observed in 6.3% of the intervention groups and in no patient of the control. No patients treated with bamlanivimab, 18.8% treated with casirivimab/imdevimab, and 14.2% in the control group developed moderate symptoms. Severe symptoms were recorded only in the control group (14.2%), including one related death. ConclusionTreatment with monoclonal SARS-CoV-2 antibodies seems to accelerate decline of virus loads, especially in the first 6 days after administration, compared to control. This may be associated with a reduced likeliness of a severe course of COVID-19.

Expanding the Pathogen Panel in Wastewater Epidemiology to Influenza and Norovirus.

Since the start of the 2019 pandemic, wastewater-based epidemiology (WBE) has proven to be a valuable tool for monitoring the prevalence of SARS-CoV-2. With methods and infrastructure being settled, it is time to expand the potential of this tool to a wider range of pathogens. We used over 500 archived RNA extracts from a WBE program for SARS-CoV-2 surveillance to monitor wastewater from 11 treatment plants for the presence of influenza and norovirus twice a week during the winter season of 2021/2022. Extracts were analyzed via digital PCR for influenza A, influenza B, norovirus GI, and norovirus GII. Resulting viral loads were normalized on the basis of NH4-N. Our results show a good applicability of ammonia-normalization to compare different wastewater treatment plants. Extracts originally prepared for SARS-CoV-2 surveillance contained sufficient genomic material to monitor influenza A, norovirus GI, and GII. Viral loads of influenza A and norovirus GII in wastewater correlated with numbers from infected inpatients. Further, SARS-CoV-2 related non-pharmaceutical interventions affected subsequent changes in viral loads of both pathogens. In conclusion, the expansion of existing WBE surveillance programs to include additional pathogens besides SARS-CoV-2 offers a valuable and cost-efficient possibility to gain public health information.

Better design leads to better results - Importance of virological outcome design in clinical trials for antiviral treatment of coronavirus disease 2019.

Better design leads to better results - Importance of virological outcome design in clinical trials for antiviral treatment of coronavirus disease 2019.

Dynamic Changes of ORF1ab and N Gene Ct Values in COVID-19 Omicron Inpatients of Different Age Groups - Beijing Municipality, China, November-December 2022.

In November 2021, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant was identified as the variant of concern and has since spread globally, replacing other cocirculating variants. To better understand the dynamic changes in viral load over time and the natural history of the virus infection, we analyzed the expression of the open reading frames 1ab (ORF1ab) and nucleocapsid (N) genes in patients infected with Omicron. We included patients initially admitted to the hospital for SARS-CoV-2 infection between November 5 and December 25, 2022. We collected daily oropharyngeal swabs for quantitative reverse transcriptase-polymerase chain reaction tests using commercial kits. We depicted the cycle threshold (Ct) values for amplification of ORF1ab and N genes from individual patients in age-specific groups in a time series. A total of 480 inpatients were included in the study, with a median age of 59 years (interquartile range, 42 to 78; range, 16 to 106). In the <45-year-old age group, the Ct values for ORF1ab and N gene amplification remained below 35 for 9.0 and 11.5 days, respectively. In the ≥80-year-old age group, the Ct values for ORF1ab and N genes stayed below 35 for 11.5 and 15.0 days, respectively, which was the longest among all age groups. The Ct values for N gene amplification took longer to rise above 35 than those for ORF1ab gene amplification. The time to test negative varied among different age groups, with viral nucleic acid shedding taking longer in older age groups compared to younger age groups. As a result, the time to resolution of Omicron infection increased with increasing age.

In vivo efficacy of 2% povidone iodine, chlorhexidine gluconate, and herbal extract mouthwash on SARS-CoV-2 viral load in saliva: A randomized clinical trial.

One of the major techniques to reduce the transmission rate of COVID-19 would be to decrease the viral titers of SARS-CoV-2 in the saliva of infected patients and it is particularly useful in a dental setting. The present study evaluated the change in salivary viral load of COVID-19 patients using povidone iodine (PI), chlorhexidine (CHX), and an herbal extract (RightSure®) oral antiviral herbal mouthwash (HM) at clinically recommended duration and concentrations. Thirty individuals with SARS-CoV-2 were randomly allocated to three groups: (1) Group 1, PI mouthwash; (2) Group 2, CHX mouthwash; and (3) Group 3, HM mouthwash. A baseline salivary throat sample was collected from all the participants who were later instructed to rinse with their respective mouthwash for 30 s. A second salivary sample was collected 30 min after rinsing. The SARS-CoV-2 viral load was analyzed using real-time reverse-transcription polymerase chain reaction wherein the cyclic threshold (Ct) values were evaluated. Independent t-test analysis reported a statistically significant difference concerning the PI group (before-after comparison) (P < 0.05). The rest of the two study groups failed to report any significant difference in the nucleocapsid gene and open reading frame 1a gene levels. While all three types of mouthwash increased the Ct values, a statistically significant difference was observed with PI mouthwash, indicating that it might potentially reduce the spread of the SARS-CoV-2 virus, especially via aerosol but further studies with larger sample size and longer follow-up periods are required to investigate this relationship.

Relationship between the inclusion/exclusion criteria and sample size in randomized controlled trials for SARS-CoV-2 entry inhibitors

The coronavirus disease 2019 (COVID-19) pandemic that has been ongoing since 2019 is still ongoing and how to control it is one of the international issues to be addressed. Antiviral drugs that reduce the viral load in terms of reducing the risk of secondary infection are important. For the general control of emerging infectious diseases, establishing an efficient method to evaluate candidate therapeutic agents will lead to a rapid response. We evaluated clinical trial designs for viral entry inhibitors that have the potential to be effective pre-exposure prophylactic drugs in addition to reducing viral load after infection. We used a previously developed simulation of clinical trials based on a mathematical model of within-host viral infection dynamics to evaluate sample sizes in clinical trials of viral entry inhibitors against COVID-19. We assumed four measures as outcomes, namely change in log10-transformed viral load from symptom onset, PCR positive ratio, log10-transformed viral load, and cumulative viral load, and then sample sizes were calculated for drugs with 99 % and 95 % antiviral efficacy. Consistent with previous results, we found that sample sizes could be dramatically reduced for all outcomes used in an analysis by adopting inclusion/exclusion criteria such that only patients in the early post-infection period would be included in a clinical trial. A comparison of sample sizes across outcomes demonstrated an optimal measurement schedule associated with the nature of the outcome measured for the evaluation of drug efficacy. In particular, the sample sizes calculated from the change in viral load and from viral load tended to be small when measurements were taken at earlier time points after treatment initiation. For the cumulative viral load, the sample size was lower than that from the other outcomes when the stricter inclusion/exclusion criteria to include patients whose time since onset is earlier than 2 days was used. We concluded that the design of efficient clinical trials should consider the inclusion/exclusion criteria and measurement schedules, as well as outcome selection based on sample size, personnel and budget needed to conduct the trial, and the importance of the outcome regarding the medical and societal requirements. This study provides insights into clinical trial design for a variety of situations, especially addressing infectious disease prevalence and feasible trial sizes. This manuscript was submitted as part of a theme issue on “Modelling COVID-19 and Preparedness for Future Pandemics”.

1079. Casirivimab and Imdevimab (CAS + IMD) Antibody Combination for the Treatment of Immunocomprised Hospitalized Patients with COVID-19

Abstract Background Immunocompromised (IC) individuals are at high risk for severe COVID-19, with high morbidity and mortality. CAS+IMD is a monoclonal antibody combination that neutralizes susceptible SARS-CoV-2 variants. We examined the natural history of COVID-19 and the efficacy and safety of CAS+IMD in IC patients (pts) hospitalized with COVID-19. Methods In a phase 1/2/3 double-blind trial (NCT04426695) conducted Jun 2020 to Apr 2021, prior to the emergence of Omicron-lineage variants, hospitalized COVID-19 pts were randomized 1:1:1 to a single 2.4 g or 8.0 g dose (combined for analyses) of CAS+IMD or placebo (P). Post hoc analyses assessed change in viral load (VL), clinical outcomes (death or mechanical ventilation [MV]), and safety for IC pts with B-cell deficiency or dysfunction (Table 1) vs all pts. Results 99/1940 (5.1%) treated pts were identified as IC (Table 2). At baseline, IC vs all pts were more likely to be seronegative for SARS-CoV-2 antibodies (68.7% vs 41.2%), and to have higher median VLs (7.21 vs 6.32 log10 copies/mL). Compared to all pts receiving P, IC pts receiving P had slower VL declines. Treatment with CAS+IMD led to a reduction in VL from baseline, with a least-squares mean time-weighted average change in VL difference vs P at Day 7 for IC pts of -0.69 (95% CI: -1.25, -0.41) vs -0.31 (CI: -0.42, -0.20) for all pts; treatment benefit persisted through Day 29 (Fig. 1). Although sample size was small for IC pts, trends in clinical outcomes of death or MV at Day 29 for IC pts (7/64 [11.0%] CAS+IMD vs 6/35 [17.2%] P) were consistent with those in all pts (200/1307 [15.3%] CAS+IMD vs 113/633 [17.9%] P). IC vs all pts treated with CAS+IMD exhibited similar rates of treatment emergent adverse events (TEAEs, 30.4% vs 26.6%), AEs of special interest (grade ≥2 hypersensitivity or infusion-related reactions; 1.4% vs 2.5%), and death (8.7% vs 12.2%; Table 3). IC and all pts exhibited fewer TEAEs with CAS+IMD vs P. Conclusion IC vs all pts hospitalized with COVID-19 were more likely to exhibit high VLs at baseline and to be seronegative. In the study, a single dose of CAS+IMD significantly reduced VL in IC pts (for variants circulating at the time, predominantly Alpha) and resulted in fewer events of death or MV. There were no new safety findings in IC pts vs all study pts. Disclosures Selin Somersan-Karakaya, PhD, BARDA: Grant/Research Support|Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Eleftherios Mylonakis, MD, PhD, Chemic Labs/KODA Therapeutics: Grant/Research Support|Cidara: Grant/Research Support|Leidos Biomedical Research Inc./NCI: Grant/Research Support|NIH/NIAID, NIH/NIGMS: Grant/Research Support|Pfizer: Grant/Research Support|Regeneron Pharmaceuticals, Inc.: Grant/Research Support|SciClone Pharmaceuticals: Grant/Research Support Ernesto Oviedo-Orta, MD, PhD, MBA, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Meagan P. O’Brien, MD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Veronica Mas Casullo, MD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Jenni Mou, PhD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Jing Xiao, PhD, Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Rafia Bhore, PhD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Adnan Mahmood, MD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Andrea T. Hooper, PhD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Mohamed Hussein, PhD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Shazia Ali, PharmD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Eduardo Forleo-Neto, MD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Gary A. Herman, MD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds Boaz Hirshberg, MD, MBA, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds David M. Weinreich, MD, Regeneron Pharmaceuticals, Inc.: Employement|Regeneron Pharmaceuticals, Inc.: Stocks/Bonds.

1411. Missed HIV Clinic Visits among Youth Living with HIV in Alabama

Abstract Background Adolescents and young adults with HIV consistently account for about one-fifth of new infections in the United States. YLWH have lower rates of testing, diagnosis, treatment engagement, and viral suppression than adults with HIV. YLWH are particularly challenged with missing medical appointments. Few studies have been published on youth living with HIV (YLWH)’s missed clinic visits and risk factors. Therefore, this study was designed to explore: 1). if the missed visits have significant associations with HIV treatment outcomes (more than 50 counts of CD4 counts drop, viral load increment, and viral suppression) in YLWH; 2). What factors are associated with missed visits for YLWH? 3) Are these factors different from the risk factors of all PLWH? Methods A retrospective study using data records from UAB Family Clinic was designed. The study used the records from March 1st 2020 to August 31st, 2021. Patients aged 16-24 were considered as YLWH. The primary outcomes are missed visits and treatment outcomes. CD4 change, Viral suppression and VL change during the study period were investigated for identifying the association between missed visit and treatment outcome. Age, gender, race, HIV transmission mode, insurance type and the viral suppression in index record were used as factors to predict missed visits. Chi-square test and logistic regression have been conducted in SAS 9.4. Results YLWH with missed visits had more viral load rebound compared to those without missed visits (p=0.04). For YLWH, gender and viral suppression in the index record have significant associations with missed visits (Gender: p=0.03, Viral suppression in index record: p=0.04). In tests among all PLWH, Race (p=0.03), Insurance type (p=0.01) and viral suppression in index record (p=0.001) are associated with missed visits. Table 1.Viral load change by missed visits.Table 2.Risk factors associated with missed visits among YLWH (n=101).Table 3.Risk factors associated with missed visits among PLWY (n=296). Conclusion Missed visits are significantly associated with viral load maintenance, and missed visits have adverse effects on treatment outcomes. Also, the risk factors for YLWH of missed visits are not identical with the risk factors for PLWH from the same cohort. Disclosures All Authors: No reported disclosures.

315. Standardized Measurement of SARS-CoV-2 Viral Load Over Time in Respiratory Compartments and in Response to Remdesivir Treatment

Abstract Background Two years into the pandemic, clinicians do not have access to a standardized measurement of SARS-CoV-2 viral load (VL) that allows for VL comparison across clinical specimens and different assays. Reliable VL measurement in diverse respiratory specimens, over time, and in response to treatments such as remdesivir (RDV), could better inform treatment and prevention. Methods To investigate the use of a standardized VL assay in respiratory specimens, we enrolled patients hospitalized with COVID-19 in Providence, RI, with/without RDV exposure; collected serial samples from 4 compartments (nasopharyngeal-NP, nasal-NA, oropharyngeal-OP, saliva-SA) in 3 visits during the 1st week of hospitalization; and characterized SARS-CoV-2 VL using a ChromaCode HDPCR™ quantitative research use only assay, calibrated to the first World Health Organization (WHO) International Standard (IS). Linear mixed effects models and associated regression coefficients were used to analyze inter-compartmental VL differences at enrollment, over time, and with/without RDV. Results Of 35 participants (60% male; 70% White, 14% Hispanic/Latino, 49% RDV exposure), all had visit 1 samples (median hospital day 1, IQR 0-2; pre-RDV for those exposed); 80% visit 2 samples (median hospital day 2, IQR 1-8); and 37% visit 3 samples (median hospital day 4, IQR 3-7). Overall, 38 NP, 67 NA, 57 OP, and 67 SA samples were collected. Mean log VLs (Log10IU/mL) differed by compartment at visit 1 (NP 6.3, NA 4.9, OP 4.1, SA 5.6, p=0.0001) and significantly decreased over time in all compartments (p&amp;lt; 0.04 for all comparisons). Log VL change over time was not significantly different between compartments or between people treated/not treated with RDV. Conclusion We successfully measured respiratory intercompartmental SARS-CoV-2 VL differences among hospitalized patients using a standardized assay calibrated to the WHO IS. Dissemination of standardized VL measurement methods will allow accurate VL comparisons across assay types quantified in IU/mL and improve assessment of the impact of COVID-19 treatments. Inter-compartmental VL differences at baseline may indicate sampling variability or different viral burden. RDV did not appear to accelerate viral decay. Disclosures Curt Beckwith, MD, Gilead Sciences, Inc: Grant/Research Support Jon Steingrimsson, PhD, Gilead: Grant/Research Support Angela Caliendo, MD, PhD, ChromaCode: Advisor/Consultant|Danaher/Cepheid: Advisor/Consultant|First Light: Advisor/Consultant|Hologic: Grant/Research Support|ID Connect: Advisor/Consultant|Quidel: Advisor/Consultant|Visby: Advisor/Consultant Rami Kantor, MD, Gilead Sciences: Grant/Research Support.

Can immune gene silencing via dsRNA feeding promote pathogenic viruses to control the globally invasive Argentine ant?

Pest control methods that can target pest species with limited environmental impacts are a conservation and economic priority. Species-specific pest control using RNA interference is a challenging but promising avenue in developing the next generation of pest management. We investigate the feasibility of manipulating a biological invader's immune system using double-stranded RNA (dsRNA) in order to increase susceptibility to naturally occurring pathogens. We used the invasive Argentine ant as a model, targeting the immunity-associated genes Spaetzle and Dicer-1 with dsRNA. We show that feeding with Spaetzle dsRNA can result in partial target gene silencing for up to 28days in the laboratory and 5days in the field. Dicer-1 dsRNA only resulted in partial gene knockdown after 2days in the laboratory. Double-stranded RNA treatments were associated with significant gene expression disruptions across immune pathways in the laboratory and to a lower extent in the field. In total, 12 viruses and four bacteria were found in these ant populations. Some changes in viral loads in dsRNA-treated groups were observed. For example, Linepithema humile Polycipivirus 2 (LhuPCV2) loads increased after 2days of treatment with Spaetzle and Dicer-1 dsRNA treatments in the laboratory. After treatment with the dsRNA in the field, after 5days the virus Linepithema humile toti-like virus 1 (LhuTLV1) was significantly more abundant. However, immune pathway disruption did not result in a consistent increase in microbial infections, nor did it alter ant abundance in the field. Some viruses even declined in abundance after dsRNA treatment. Our study explored the feasibility of lowering a pest's immunity as a control tool. We demonstrate that it is possible to alter immune gene expression of pest species and pathogen loads, although in our specific system the affected pathogens did not appear to influence pest abundance. We provide suggestions on future directions for dsRNA-mediated immune disruption in pest species, including potential avenues to improve dsRNA delivery as well as the importance of pest and pathogen biology. Double-stranded RNA targeting immune function might be especially useful for pest control in systems in which viruses or other microorganisms are prevalent and have the potential to be pathogenic.

Phase I Study Evaluating Outcomes of Autologous HIV-Specific T Cells Targeting Non-Escaped Epitopes (HST-NEET) Therapy in HIV+ Individuals on ART (NCT03485963)

While allogeneic bone marrow transplant (alloBMT) can offer a curative approach for HIV, successes have been limited. HIV-specific CD8+ T cells may be harnessed to eliminate or control HIV, but these responses are limited by factors including viral immune escape mutations. In this study, we hypothesized that T cell therapies targeting conserved HIV epitopes would be safe and show in vivo antiviral activity. This phase I clinical trial (NCT03485963) evaluated the safety, immunologic and virologic responses of a novel HIV-1 multi-antigen specific T cell therapy (HST-NEET) targeting HIV Nef and conserved epitopes of Gag and Pol in people with HIV suppressed on antiretroviral therapy (ART). We investigated whether infused autologous HST-NEETs expand, persist, and elicit anti-viral responses in vivo. Six participants with HIV (ages 33-57 years, 3 males and 2 females identifying as African or African American, 1 male identifying as White) received two infusions (2x107 cells/m2 BSA/dose) of HST-NEETs without prescribed lymphodepletion. Treatment follow-up was conducted for 48 weeks post-infusions. RESIST001 and 005 received infusions 4 weeks apart. RESIST003 and 004 received infusions >4 weeks apart (58 weeks and 35 weeks, respectively) due to delays caused by the COVID-19 pandemic. RESIST006 and 007 received infusions 2 weeks apart. RESIST004 was hospitalized for COVID-19 between infusions, but no attributable severe adverse events were observed for any participant irrespective of the timing of their infusions. All participants remained on ART throughout the study period. To determine the epitope specificities and breadth of the T cell repertoire within the infusion products, IFNγ ELISPOT and intracellular cytokine flow cytometric assays were used to evaluate antigen-specific responses to HIV Gag, Pol, and Nef in the HST-NEET products. These studies also support tracking of the infused T cells in vivo. ELISPOT, flow cytometry and TCR sequencing were conducted to evaluate expansion and persistence of HIV-specific T cell clones in vivo. Pre- and post-infusion, the genetically intact HIV reservoir was quantified using the intact proviral DNA assay (IPDA), while HIV Envelope gp120 (Env)-specific antibody levels were assessed using ELISA. HST-NEET infusion products met clinical dose requirements, with predominantly CD3+CD8+ (med 70.7%, range 19% to 95.6%) populations expressing effector memory (CD45RO+CCR7-CD62L-) (86.8-98.4%) markers. HST-NEET products had specificity for 1-3 viral antigens with a dominance of Nef-specific responses (Table 1). Epitope mapping of the products identified 10 recognized epitopes, including repeated Nef epitopes associated with the HLA-B07 supertype. Post-infusion studies (including TCR sequencing) for RESIST001 revealed marked in vivo expansion and persistence of T cells recognizing the same Nef peptide in the HST-NEETs product. However, no changes in HIV gp120 antibody levels or viral load were observed. RESIST005 HST-NEETs recognized 3 Nef epitopes but again, no changes in viral load were observed. RESIST004 also received a predominantly Nef-specific HST-NEET product eliciting expansion of Nef-specific T cells in vivo post-infusion. In contrast to RESIST001 and 005, a decrease in HIV reservoir size was observed in RESIST004 post-infusion #1 from 32.1 (pre) to 0 (at 36 weeks) intact proviruses/million CD4+ T cells (INTACT/M), which remained low at 8.4 INTACT/M post-infusion #2. RESIST003 products were broadly specific, mapping to 4 HIV Pol and 2 Nef CD8-restricted epitopes and at 5 weeks post-infusion #1, HIV reservoir size markedly decreased from 24.4 to 0 INTACT/M. Further, post HST-NEET infusion #2, the levels remained low (mean 6.3 INTACT/M). The immune and anti-viral studies are ongoing for RESIST006 and 007. In summary, these data suggest that infusions of HST-NEETs are safe, can elicit expansion and persistence of HIV-specific T cell populations post-infusion even without prescribed lymphodepletion, and may be associated with durable decreases in the HIV reservoir, as measured by intact proviruses. Although these studies are ongoing, the infusion of HST-NEETs may be a viable therapeutic strategy in the lymphodepleted setting post autologous and allogeneic stem cell transplant as is also being evaluated in 2 ongoing clinical trials (NCT04975698 and NCT04248192, respectively). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Aspects of cytomegalovirus reactivation in critically ill patients

Cytomegalovirus plays an essential role in human pathology. Primary infection usually occurs in childhood and subsequently, a lifelong latency is formed which the virus replicates by evading the immune response. In recent years, more and more researchers have concluded that cytomegalovirus reactivation may occur in critically ill patients. Despite the available evidence, data on reactivation in this group of patients are limited by the relatively small sample size, the variety of patient groups studied, the differences in study methodology, and the variability in reported results, which excludes the possibility of summarizing the results.This study aimed to determine the frequency of reactivation of cytomegalovirus infection in critically ill patients and to identify its main clinical features.Materials and methods. The study included 118 critically ill patients with severe bacterial and viral-bacterial infections accompanied by multiple organ dysfunction. Cytomegalovirus reactivation was determined by the detection of DNA in combination with the presence of IgG.Results. Reactivation was detected in 36.4% of cases. Frequency and terms of reactivation in blood and sputum as well as trends of viral load changes in dynamics were shown. The main clinical features of reactivation in different pathologies (sepsis of bacterial etiology, COVID-19, non-septic critical patients) were noted. HCMV DNA was more frequently detected in the blood of septic patients (44.8%) compared with COVID-19 (13.0%, p&lt;0.05) and non-septic critically ill patients (19.2%, p&lt;0.05). COVID-19 was characterized not only by lower detection of HCMV DNA in the blood but also by the lowest viral loads (p&lt;0.05). HCMV DNA in sputum was detected comparably frequently in sepsis (38.1%) and COVID-19 (33.3%), but the highest viral loads were characteristic of patients with sepsis (p&lt;0.05).

Atovaquone for treatment of COVID-19: A prospective randomized, double-blind, placebo-controlled clinical trial.

Background: An in silico screen was performed to identify FDA approved drugs that inhibit SARS-CoV-2 main protease (Mpro), followed by in vitro viral replication assays, and in vivo pharmacokinetic studies in mice. These studies identified atovaquone as a promising candidate for inhibiting viral replication. Methods: A 2-center, randomized, double-blind, placebo-controlled trial was performed among patients hospitalized with COVID-19 infection. Enrolled patients were randomized 2:1 to atovaquone 1500 mg BID versus matched placebo. Patients received standard of care treatment including remdesivir, dexamethasone, or convalescent plasma as deemed necessary by the treating team. Saliva was collected at baseline and twice per day for up to 10 days for RNA extraction for SARS-CoV-2 viral load measurement by quantitative reverse-transcriptase PCR. The primary outcome was the between group difference in log-transformed viral load (copies/mL) using a generalized linear mixed-effect models of repeated measures from all samples. Results: Of the 61 patients enrolled; 41 received atovaquone and 19 received placebo. Overall, the population was predominately male (63%) and Hispanic (70%), with a mean age of 51 years, enrolled a mean of 5 days from symptom onset. The log10 viral load was 5.25 copies/mL vs. 4.79 copies/mL at baseline in the atovaquone vs. placebo group. Change in viral load did not differ over time between the atovaquone plus standard of care arm versus the placebo plus standard of care arm. Pharmacokinetic (PK) studies of atovaquone plasma concentration demonstrated a wide variation in atovaquone levels, with an inverse correlation between BMI and atovaquone levels, (Rho −0.45, p = 0.02). In post hoc analysis, an inverse correlation was observed between atovaquone levels and viral load (Rho −0.54, p = 0.005). Conclusion: In this prospective, randomized, placebo-controlled trial, atovaquone did not demonstrate evidence of enhanced SARS-CoV-2 viral clearance compared with placebo. However, based on the observed inverse correlation between atovaquone levels and viral load, additional PK-guided studies may be warranted to examine the antiviral effect of atovaquone in COVID-19 patients.

Evaluation of blood samples collected by dried blood spots (DBS) method for hepatitis B virus DNA quantitation and its stability under real life conditions

We evaluated the diagnostic performance of dried blood spots (DBS) compared to plasma for detection and quantification of HBV-DNA under real-life conditions. Blood specimens from 100 known cases of chronic hepatitis B (CHB) requested for quantitative HBV-DNA were included. In a subset of 20 patients, three sets of DBS cards were prepared, one kept at -80°C, the other two kept at room temperature for 7 and 14 days, respectively. DBS method demonstrated sensitivity, specificity, and positive predictive value of 95.3%, 100%, and 100%, respectively in comparison to plasma. The mean HBV-DNA load in plasma was 4.8 log10 IU/ml while in DBS was 4.3 log10 IU/ml with a strong correlation (R2=0.9087). No significant change in viral load was observed at room temperature for up to 14 days. This study suggests that DBS for HBV viral-load quantitation is a good alternative to plasma as it is stable during storage at room temperature and therefore allows easy handling, storage, and transport of specimens in resource-limited settings.