Showing papers on "Viremia published in 2021"

COVID-19 Vaccines May Not Prevent Nasal SARS-CoV-2 Infection and Asymptomatic Transmission.

Abstract: Current COVID-19 vaccine candidates are administered by injection and designed to produce an IgG response, preventing viremia and the COVID-19 syndrome. However, systemic respiratory vaccines generally provide limited protection against viral replication and shedding within the airway, as this requires a local mucosal secretory IgA response. Indeed, preclinical studies of adenovirus and mRNA candidate vaccines demonstrated persistent virus in nasal swabs despite preventing COVID-19. This suggests that systemically vaccinated patients, while asymptomatic, may still be become infected and transmit live virus from the upper airway. COVID-19 is known to spread through respiratory droplets and aerosols. Furthermore, significant evidence has shown that many clinic and surgical endonasal procedures are aerosol generating. Until further knowledge is acquired regarding mucosal immunity following systemic vaccination, otolaryngology providers should maintain precautions against viral transmission to protect the proportion of persistently vulnerable patients who exhibit subtotal vaccine efficacy or waning immunity or who defer vaccination.

Emerging RNA-Dependent RNA Polymerase Mutation in a Remdesivir-Treated B-cell Immunodeficient Patient With Protracted Coronavirus Disease 2019.

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly discovered virus for which remdesivir is the only antiviral available. We report the occurrence of a mutation in RdRP (D484Y) following treatment with remdesivir in a 76-year-old female with post-rituximab B-cell immunodeficiency and persistent SARS-CoV-2 viremia. A cure was achieved after supplementation with convalescent plasma.

SARS-CoV-2 Viremia is Associated with COVID-19 Severity and Predicts Clinical Outcomes.

Abstract: BACKGROUND: SARS-CoV-2 viral RNA (vRNA) is detected in the bloodstream of some patients with COVID-19 ("RNAemia") but it is not clear whether this RNAemia reflects viremia (i.e., virus particles) and how RNAemia/viremia is related to host immune responses and outcomes. METHODS: SARS-CoV-2 vRNA was quantified by ultra-sensitive RT-PCR in plasma samples (0.5-1.0 ml) from observational cohorts of 51 COVID-19 patients including 9 outpatients, 19 hospitalized (non-ICU), and 23 ICU patients, and vRNA levels compared with cross-sectional indices of COVID-19 severity and prospective clinical outcomes. We used multiple imaging methods to visualize virions in pelleted plasma. RESULTS: SARS-CoV-2 vRNA was detected in plasma of 100%, 52.6% and 11.1% of ICU, non-ICU, and outpatients respectively. Virions were detected in plasma pellets by electron tomography and immunostaining. Plasma vRNA levels were significantly higher in ICU > non-ICU > outpatients (p 6,000 copies/ml was strongly associated with mortality (HR: 10.7). Levels of vRNA were significantly associated with several inflammatory biomarkers (p<0.01) but not with plasma neutralizing antibody titers (p=0.8). CONCLUSIONS: Visualization of virus particles in plasma indicates that SARS-CoV-2 RNAemia is due, at least in part, to viremia. The levels of SARS-CoV-2 RNAemia quantified by ultrasensitive RT-PCR correlate strongly with disease severity, patient outcome and specific inflammatory biomarkers but not neutralizing antibody titers.

SARS-CoV-2 viremia is associated with distinct proteomic pathways and predicts COVID-19 outcomes.

Abstract: BACKGROUNDSARS-CoV-2 plasma viremia has been associated with severe disease and death in COVID-19 in small-scale cohort studies. The mechanisms behind this association remain elusive.METHODSWe evaluated the relationship between SARS-CoV-2 viremia, disease outcome, and inflammatory and proteomic profiles in a cohort of COVID-19 emergency department participants. SARS-CoV-2 viral load was measured using a quantitative reverse transcription PCR-based platform. Proteomic data were generated with Proximity Extension Assay using the Olink platform.RESULTSThis study included 300 participants with nucleic acid test-confirmed COVID-19. Plasma SARS-CoV-2 viremia levels at the time of presentation predicted adverse disease outcomes, with an adjusted OR of 10.6 (95% CI 4.4-25.5, P < 0.001) for severe disease (mechanical ventilation and/or 28-day mortality) and 3.9 (95% CI 1.5-10.1, P = 0.006) for 28-day mortality. Proteomic analyses revealed prominent proteomic pathways associated with SARS-CoV-2 viremia, including upregulation of SARS-CoV-2 entry factors (ACE2, CTSL, FURIN), heightened markers of tissue damage to the lungs, gastrointestinal tract, and endothelium/vasculature, and alterations in coagulation pathways.CONCLUSIONThese results highlight the cascade of vascular and tissue damage associated with SARS-CoV-2 plasma viremia that underlies its ability to predict COVID-19 disease outcomes.FUNDINGMark and Lisa Schwartz; the National Institutes of Health (U19AI082630); the American Lung Association; the Executive Committee on Research at Massachusetts General Hospital; the Chan Zuckerberg Initiative; Arthur, Sandra, and Sarah Irving for the David P. Ryan, MD, Endowed Chair in Cancer Research; an EMBO Long-Term Fellowship (ALTF 486-2018); a Cancer Research Institute/Bristol Myers Squibb Fellowship (CRI2993); the Harvard Catalyst/Harvard Clinical and Translational Science Center (National Center for Advancing Translational Sciences, NIH awards UL1TR001102 and UL1TR002541-01); and by the Harvard University Center for AIDS Research (National Institute of Allergy and Infectious Diseases, 5P30AI060354).

The Longest Persistence of Viable SARS-CoV-2 With Recurrence of Viremia and Relapsing Symptomatic COVID-19 in an Immunocompromised Patient-A Case Study.

Abstract: Background Immunocompromised patients show prolonged shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nasopharyngeal swabs. We report a case of prolonged persistence of viable SARS-CoV-2 associated with clinical relapses of coronavirus disease 2019 (COVID-19) in a patient with mantle cell lymphoma who underwent treatment with rituximab, bendamustine, cytarabine with consequent lymphopenia and hypogammaglobulinemia. Methods Nasopharyngeal swabs and blood samples were tested for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR). On 5 positive nasopharyngeal swabs, we performed viral culture and next-generation sequencing. We analyzed the patient's adaptive and innate immunity to characterize T- and NK-cell subsets. Results SARS-CoV-2 RT-PCR on nasopharyngeal swabs samples remained positive for 268 days. All 5 performed viral cultures were positive, and genomic analysis confirmed a persistent infection with the same strain. Viremia resulted positive in 3 out of 4 COVID-19 clinical relapses and cleared each time after remdesivir treatment. The T- and NK-cell dynamic was different in aviremic and viremic samples, and no SARS-CoV-2-specific antibodies were detected throughout the disease course. Conclusions In our patient, SARS-CoV-2 persisted with proven infectivity for >8 months. Viremia was associated with COVID-19 relapses, and remdesivir treatment was effective in viremia clearance and symptom remission, although it was unable to clear the virus from the upper respiratory airways. During the viremic phase, we observed a low frequency of terminal effector CD8+ T lymphocytes in peripheral blood; these are probably recruited in inflammatory tissue for viral eradication. In addition, we found a high level of NK-cell repertoire perturbation with relevant involvement during SARS-CoV-2 viremia.

NITD-688, a pan-serotype inhibitor of the dengue virus NS4B protein, shows favorable pharmacokinetics and efficacy in preclinical animal models.

Abstract: Dengue virus (DENV) is a mosquito-borne flavivirus that poses a threat to public health, yet no antiviral drug is available. We performed a high-throughput phenotypic screen using the Novartis compound library and identified candidate chemical inhibitors of DENV. This chemical series was optimized to improve properties such as anti-DENV potency and solubility. The lead compound, NITD-688, showed strong potency against all four serotypes of DENV and demonstrated excellent oral efficacy in infected AG129 mice. There was a 1.44-log reduction in viremia when mice were treated orally at 30 milligrams per kilogram twice daily for 3 days starting at the time of infection. NITD-688 treatment also resulted in a 1.16-log reduction in viremia when mice were treated 48 hours after infection. Selection of resistance mutations and binding studies with recombinant proteins indicated that the nonstructural protein 4B is the target of NITD-688. Pharmacokinetic studies in rats and dogs showed a long elimination half-life and good oral bioavailability. Extensive in vitro safety profiling along with exploratory rat and dog toxicology studies showed that NITD-688 was well tolerated after 7-day repeat dosing, demonstrating that NITD-688 may be a promising preclinical candidate for the treatment of dengue.

Immunotherapy during the acute SHIV infection of macaques confers long-term suppression of viremia.

Abstract: We report that combination bNAb immunotherapy initiated on day 3 post-infection (PI) maintained durable CD8+ T cell-mediated suppression of SHIVAD8 viremia and preinoculation levels of CD4+ T cells in 9 of 13 treated monkeys during nearly 6 yr of observation, as assessed by successive CD8+ T cell-depletion experiments. In an extension of that study, two treatment interventions (bNAbs alone or cART plus bNAbs) beginning on week 2 PI were conducted and conferred controller status to 7 of 12 monkeys that was also dependent on control mediated by CD8+ cells. However, the median time to suppression of plasma viremia following intervention on week 2 was markedly delayed (85 wk) compared with combination bNAb immunotherapy initiated on day 3 (39 wk). In both cases, the principal correlate of virus control was the induction of CD8+ T cellular immunity.

Search for SARS-CoV-2 RNA in platelets from COVID-19 patients.

Abstract: The frequent finding of thrombocytopenia in patients with severe SARS-CoV-2 infection (COVID-19) and previous evidence that several viruses enter platelets suggest that SARS-CoV-2 might be internalized by platelets of COVID-19. Aim of our study was to assess the presence of SARS-CoV-2 RNA in platelets from hospitalized patients with aconfirmed diagnosis of COVID-19. RNA was extracted from platelets, leukocytes and serum from 24 COVID-19 patients and 3 healthy controls, real-time PCR and ddPCR for viral genes were carried out. SARS-CoV-2 RNA was not detected in any of the samples analyzed nor in healthy controls, by either RT-PCR or ddPCR, while RNA samples from nasopharyngeal swabs of COVID-19 patients were correctly identified. Viral RNA was not detected independently of viral load, of positive nasopharyngeal swabs, or viremia, the last detected in only one patient (4.1%). SARS-CoV-2 entry in platelets is not acommon phenomenon in COVID-19 patients, differently from other viral infections.

SARS-CoV-2 Viremia is Associated with Distinct Proteomic Pathways and Predicts COVID-19 Outcomes

Abstract: Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) plasma viremia has been associated with severe disease and death in coronavirus disease 2019 (COVID-19) in small-scale cohort studies. The mechanisms behind this association remain elusive. Methods We evaluated the relationship between SARS-CoV-2 viremia, disease outcome, inflammatory and proteomic profiles in a cohort of COVID-19 emergency department participants. SARS-CoV-2 viral load was measured using qRT-PCR based platform. Proteomic data were generated with Proximity Extension Assay (PEA) using the Olink platform. Results Three hundred participants with nucleic acid test-confirmed COVID-19 were included in this study. Levels of plasma SARS-CoV-2 viremia at the time of presentation predicted adverse disease outcomes, with an adjusted odds ratio (aOR) of 10.6 (95% confidence interval [CI] 4.4, 25.5, P<0.001) for severe disease (mechanical ventilation and/or 28-day mortality) and aOR of 3.9 (95%CI 1.5, 10.1, P=0.006) for 28-day mortality. Proteomic analyses revealed prominent proteomic pathways associated with SARS-CoV-2 viremia, including upregulation of SARS-CoV-2 entry factors (ACE2, CTSL, FURIN), heightened markers of tissue damage to the lungs, gastrointestinal tract, endothelium/vasculature and alterations in coagulation pathways. Conclusions These results highlight the cascade of vascular and tissue damage associated with SARS-CoV-2 plasma viremia that underlies its ability to predict COVID-19 disease outcomes.

In-depth single-cell analysis of translation-competent HIV-1 reservoirs identifies cellular sources of plasma viremia.

Abstract: Clonal expansion of HIV-infected cells contributes to the long-term persistence of the HIV reservoir in ART-suppressed individuals. However, the contribution from cell clones that harbor inducible proviruses to plasma viremia is poorly understood. Here, we describe a single-cell approach to simultaneously sequence the TCR, integration sites and proviral genomes from translation-competent reservoir cells, called STIP-Seq. By applying this approach to blood samples from eight participants, we show that the translation-competent reservoir mainly consists of proviruses with short deletions at the 5'-end of the genome, often involving the major splice donor site. TCR and integration site sequencing reveal that cell clones with predicted pathogen-specificity can harbor inducible proviruses integrated into cancer-related genes. Furthermore, we find several matches between proviruses retrieved with STIP-Seq and plasma viruses obtained during ART and upon treatment interruption, suggesting that STIP-Seq can capture clones that are responsible for low-level viremia or viral rebound.

Broadly neutralizing antibody–derived CAR T cells reduce viral reservoir in individuals infected with HIV-1

Abstract: Background Chimeric antigen receptor (CAR)-modified T cells have emerged as a novel approach to treat malignant tumors. This strategy has also been proposed for the treatment of HIV-1 infection. We have developed a broadly neutralizing antibody (bNAb)-derived CAR-T cell therapy which can exerted specific cytotoxic activity against HIV-1-infected cells. Methods We conducted an open-label trial of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of bNAb-derived CAR-T cell therapy in HIV-1-infected individuals who were undergoing analytical interruption of antiretroviral therapy (ART). Results A total of 14 participants completed only a single administration of bNAb-derived CAR-T cells. CAR-T administration was safe and well tolerated. Six participants discontinued ART, and viremia rebound occurred in all of them, with a 5.3-week median time. Notably, the cell-associated viral RNA and intact proviruses decreased significantly after CAR-T treatment. Analyses of HIV-1 variants before or after CAR-T administration suggested that CAR-T cells exerted pressure on rebound viruses, resulting in a selection of viruses with less diversity and mutations against CAR-T-mediated cytotoxicity. Conclusions No safety concerns were identified with adoptive transfer of bNAb-derived CAR-T cells. They reduced viral reservoir. All the rebounds were due to preexisting or emergence of viral escape mutations. Trial registration ClinicalTrials.gov number, NCT03240328. Funding Ministry of Science and Technology of China, National Natural Science Foundation of China, and Department of Science and Technology of Guangdong Province.

African Swine Fever Virus Bearing an I226R Gene Deletion Elicits Robust Immunity in Pigs to African Swine Fever.

Abstract: African swine fever (ASF) is a severe hemorrhagic infectious disease in pigs caused by African swine fever virus (ASFV), leading to devastating economic losses in epidemic regions. Its control currently depends on thorough culling and clearance of the diseased and surrounding suspected pigs. An ASF vaccine has been extensively explored for years worldwide, especially in hog-intensive areas where it is highly desired, but it is still unavailable for numerous reasons. Here, we report another ASF vaccine candidate, named SY18ΔI226R, bearing a deletion of the I226R gene with a replacement of an enhanced green fluorescent protein (eGFP) expression cassette at the right end of the viral genome. This deletion results in the complete loss of virulence of SY18 as the gene-deleted strain does not cause any clinical symptoms in all pigs inoculated with a dosage of either 104.0 or 107.0 50% tissue culture infective doses (TCID50). Apparent viremia with a gradual decline was monitored, while virus shedding was detected only occasionally in oral or anal swabs. ASFV-specific antibody appeared at 9 days postinoculation. After intramuscular challenge with its parental strain ASFV SY18 at 21 days postinoculation, all the challenged pigs survived, without obvious febrile or abnormal clinical signs. No viral DNA could be detected upon the dissection of any tissue when viremia disappeared. These results indicated that SY18ΔI226R is safe in swine and elicits robust immunity to virulent ASFV infection. IMPORTANCE Outbreaks of African swine fever have resulted in devastating losses to the swine industry worldwide, but there is currently no commercial vaccine available. Although several vaccine candidates have been reported, none has been approved for use for several reasons, especially ones concerning biosafety. Here, we identified a new undescribed functional gene, I226R. When deleted from the ASFV genome, the virus completely loses its virulence in swine. Importantly, pigs infected with this gene-deleted virus were resistant to infection by intramuscular challenge with 102.5 or 104.0 TCID50 of its virulent parental virus. Furthermore, the nucleic acid of the gene-deleted virus and its virulent parental virus was rarely detected from oral or anal swabs. Viruses could not be detected in any tissues after necropsy when viremia became negative, indicating that robust immunity was achieved. Therefore, SY18ΔI226R is a novel, ideal, and efficacious vaccine candidate for genotype II ASF.

SARS-CoV-2 RNA in plasma samples of COVID-19 affected individuals: a cross-sectional proof-of-concept study.

Abstract: Recent studies showed that plasma SARS-CoV-2 RNA seems to be associated with worse COVID-19 outcome. However, whether specific population can be at higher risk of viremia are to date unexplored. This cross-sectional proof-of-concept study included 41 SARS-CoV-2-positive adult individuals (six affected by haematological malignancies) hospitalized at two major hospital in Milan, for those demographic, clinical and laboratory data were available. SARS-CoV-2 load was quantified by ddPCR in paired plasma and respiratory samples. To assess significant differences between patients with and patients without viremia, Fisher exact test and Wilcoxon test were used for categorical and continuous variables, respectively. Plasma SARS-CoV-2 RNA was found in 8 patients (19.5%), with a median (IQR) value of 694 (209–1023) copies/mL. Viremic patients were characterized by an higher mortality rate (50.0% vs 9.1%; p = 0.018) respect to patients without viremia. Viremic patients were more frequently affected by haematological malignancies (62.5% vs. 3.0%; p < 0.001), and had higher viral load in respiratory samples (9,404,000 [586,060-10,000,000] vs 1560 [312–25,160] copies/mL; p = 0.002). Even if based on a small sample population, this proof-of-concept study poses the basis for an early identification of patients at higher risk of SARS-CoV-2 viremia, and therefore likely to develop severe COVID-19, and supports the need of a quantitative viral load determination in blood and respiratory samples of haematologic patients with COVID-19 in order to predict prognosis and consequently to help their further management.

Detection of SARS-CoV-2 RNA in serum is associated with increased mortality risk in hospitalized COVID-19 patients.

Abstract: COVID-19 has overloaded national health services worldwide. Thus, early identification of patients at risk of poor outcomes is critical. Our objective was to analyse SARS-CoV-2 RNA detection in serum as a severity biomarker in COVID-19. Retrospective observational study including 193 patients admitted for COVID-19. Detection of SARS-CoV-2 RNA in serum (viremia) was performed with samples collected at 48-72 h of admission by two techniques from Roche and Thermo Fischer Scientific (TFS). Main outcome variables were mortality and need for ICU admission during hospitalization for COVID-19. Viremia was detected in 50-60% of patients depending on technique. The correlation of Ct in serum between both techniques was good (intraclass correlation coefficient: 0.612; p < 0.001). Patients with viremia were older (p = 0.006), had poorer baseline oxygenation (PaO2/FiO2; p < 0.001), more severe lymphopenia (p < 0.001) and higher LDH (p < 0.001), IL-6 (p = 0.021), C-reactive protein (CRP; p = 0.022) and procalcitonin (p = 0.002) serum levels. We defined "relevant viremia" when detection Ct was < 34 with Roche and < 31 for TFS. These thresholds had 95% sensitivity and 35% specificity. Relevant viremia predicted death during hospitalization (OR 9.2 [3.8-22.6] for Roche, OR 10.3 [3.6-29.3] for TFS; p < 0.001). Cox regression models, adjusted by age, sex and Charlson index, identified increased LDH serum levels and relevant viremia (HR = 9.87 [4.13-23.57] for TFS viremia and HR = 7.09 [3.3-14.82] for Roche viremia) as the best markers to predict mortality. Viremia assessment at admission is the most useful biomarker for predicting mortality in COVID-19 patients. Viremia is highly reproducible with two different techniques (TFS and Roche), has a good consistency with other severity biomarkers for COVID-19 and better predictive accuracy.

Monoclonal antibody-mediated neutralization of SARS-CoV-2 in an IRF9-deficient child.

Abstract: We describe an unvaccinated child at risk for life-threatening COVID-19 due to an inherited deficiency of IRF9, which governs ISGF-3-dependent responses to type I and III interferons (IFN). She was admitted, with a high nasal SARS-CoV-2 load on day 1 of upper respiratory tract infection. She was viremic on day 2 and received casirivimab and imdevimab. Her clinical manifestations and viremia disappeared on days 3 and 4, respectively. Circulating SARS-CoV-2 virus induced the expression of IFN-stimulated genes in leukocytes on day 1, whereas the secretion of blood type I IFNs, which peaked on day 4, did not. Antibody-mediated SARS-CoV-2 neutralization is, therefore, sufficient to overcome a deficiency of antiviral IFNs.

Detection of SARS-CoV-2 viremia before onset of COVID-19 symptoms in an allo-transplanted patient with acute leukemia.

Abstract: COVID-19 is a life threatening disease, caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patients with undergoing treatment for hematologic malignancies including hematopoietic stem cell transplantation are considered to be at particular risk for fatal outcomes [1, 2]. This report describes for the first time the detection of SARS-CoV-2 viremia prior to the onset of symptoms and diagnosis of COVID-19 in a 51-year-old patient with acute myeloid leukemia (AML) and relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Notably, we illustrate that SARS-CoV-2 viremia inversely correlates with anti-SARS-CoV-2 antibody production, which predates negativity in respiratory samples for 4 weeks. A 51-year-old female patient was admitted to the University Hospital of Cologne on March 9, 2020, with herpes zoster involving C8/Th1 and Enterococcus faecalis bloodstream infection in the context of a third relapse of a FLT-3 mutated AML after an allo-HSCT from her HLA-identical brother in 2017. At this point, she presented with CTC (Common Toxicity Criteria) grade IV neutropenia and thrombocytopenia. Antibiotic and antiviral treatment was initiated. The patient received Midostaurin and Gemtuzumab ozogamicin as treatment for the relapsed AML. Under this therapy, the general condition of the patient improved, with symptoms and inflammatory parameters retreating. However, on March 21, 2020, 11 days after admission, the patient developed fever with temperatures up to 38.4 °C combined with a dry cough and fatigue. SARS-CoV-2 infection was confirmed in a PCR analysis of a pharyngeal swab on March 23, 2020. Laboratory results showed an increase in inflammatory parameters such as ferritin, C-reactive protein (CRP) and interleukin (IL)-6 (Fig. 1). A computed tomography (CT) scan showed infiltrates characteristic of COVID-19 pneumonia (see Supplementary Fig. 1). The patient rapidly developed dyspnea, peripheral blood oxygen saturation decreased and non-invasive oxygen supplementation was required (Fig. 1). Following, IL-6 and ferritin levels increased fast correlating with clinical decline. Under the assumption of a hyperinflammatory syndrome, the patient received Tocilizumab twice in a 7 days interval due to not satisfactory recovery after the first dose. After anti-IL6 treatment, symptoms decreased as well as inflammatory parameters (Fig. 1). The patient recovered slowly in the following 6 weeks: fever subsided with the exception of a new catheter-associated soft-tissue infection after 6 weeks. Oxygen supplementation could be slowly reduced and a progressive decrease of inflammatory parameters was observed. The patient was finally discharged seven weeks after admission and referred to our outpatient clinic for further treatment of her AML. a Real-time PCR Cycle threshold (RT-PCR Ct) values for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in blood samples and IgG antibody ratios. The dotted horizontal line marks the detection line of RNA, as well as the threshold for antibody seroconversion. Onset of symptoms defined as day 0, presented with grey vertical dotted line. Onset and end of viremia presented with red vertical dotted lines. Negative RT-PCR test results are displayed as Ct (Cycle threshold) values of 42. b RT-PCR Ct values for SARS-CoV-2 RNA in respiratory samples and corresponding IgG antibody ratios. c Maximum Temperature measured on each day in °C and maximum oxygen supply in l/min on each day over the course of disease. Fever is defined as a temperature >38.0 °C. d Levels of CRP (C-reactive protein) in mg/l, ferritin in μg/l and interleukin (IL)-6 in ng/l over the course of disease. Respiratory and plasma specimens were collected routinely for SARS-CoV-2 real-time PCR (RT-PCR) and antibody testing (detailed information is reported in Supplementary Materials). The publication of this data was approved by the Institutional Review Board of the University of Cologne (20-1254) and the patient’s written informed consent obtained. SARS-CoV-2 viremia was first detected on March 19, 2020, 2 days before the first symptoms (fever and dry cough) occurred and inflammatory parameters began to rise. Thus, we confirmed the presence of SARS-CoV-2 viremia 4 days before the detection of SARS-CoV-2 RNA in pharyngeal swab (Fig. 1). Analyzing the virus-related molecular and serological parameters throughout the course of disease, the progressive increase of detected SARS-CoV-2 RNA in the evaluated plasma samples reached a peak 8 days after the first detection in blood, whereas the last positive evidence of SARS-CoV-2 RNA in plasma was observed on April 14, 2020. On the same date, corresponding to 24 days after initial symptoms, SARS-CoV-2 specific IgA and IgG antibodies were detected (above threshold of 1.1). Along the course, the increase of specific SARS-CoV-2 antibody levels correlated with viral clearance from the blood (Fig. 1). However, SARS-CoV-2 RT-PCR from respiratory samples remained positive for three more weeks (7 weeks in total), despite occurrence of seroconversion, disappearance of COVID-19 related symptoms, and normalized inflammatory markers. Finally, 51 days after the onset of symptoms, the patient was tested SARS-CoV-2 negative in respiratory specimen (Fig. 1). The present report describes a case of SARS-CoV-2 viremia, preceding COVID-19 symptoms for 2 days, indicating a clear link between the observed SARS-CoV-2 viremia and beginning of COVID-19 symptoms. Consecutively, this suggests that SARS-CoV-2 viremia might play a more crucial role in COVID-19 than previously assumed because viremia before onset of symptoms is possible at least in a portion of cases. So far, SARS-CoV-2 RNA detected in blood has been considered a bystander effect, assuming that it is an avital virus component [3]. However, the detection of viremia prior to the onset of clinical symptoms suggests a systemic infection with...

Extent of Cytomegalovirus Replication in the Human Host Depends on Variations of the HLA-E/UL40 Axis.

Abstract: Human cytomegalovirus (HCMV) may cause severe infections in lung transplant recipients (LTRs). In response to HCMV infections, a subset of NKG2C+ NK cells expands, which limits HCMV replication and is characterized by high expression of the activating NKG2C/CD94 and absence of the inhibitory NKG2A/CD94 receptor. Both receptors bind to HLA-E, which is stabilized by HCMV-encoded UL40 peptides. HLA-E and UL40 occur as different genetic variants. In this study, we investigated the interplay between the human NK cell response and the infecting HCMV-UL40 strain, and we assessed the impact of HCMV-UL40 and of donor- and recipient-encoded HLA-E*0101/0103 variants on HCMV replication after lung transplantation. We included 137 LTRs displaying either no or low- or high-level (>1,000 copies/ml plasma) viremia. HCMV-UL40 and HLA-E*0101/0103 variants were determined. UL40 diversity was investigated by next-generation sequencing. UL40 peptide-dependent NK cell cytotoxicity was assessed by flow cytometry. Donor-encoded HLA-E*0101/0103 was significantly associated with development of high-level viremia after transplantation (P = 0.007). The HCMV-UL40 variant VMAPRTLIL occurred significantly more frequently in highly viremic LTRs, and the variant VMTPRTLIL occurred significantly more frequently in low-viremic LTRs (P = 0.004). This difference was associated with a better inhibition of NKG2A+ NKG2C- NK cells by VMAPRTLIL (P < 0.001). In LTRs with repeated high-level viremic episodes, HCMV strains with UL40 variants displaying low affinity to the patients' HLA-E variant emerged over time. The HLA-E-UL40 axis has a substantial impact on the level of HCMV replication in LTRs. The interplay between UL40 peptide variants, the recipient HLA-E status, and the activation of inhibitory NKG2A+ NKG2C- cells is of major importance for development of high-level viremia after lung transplantation.IMPORTANCE Infection with human cytomegalovirus (HCMV) is associated with substantial morbidity in immunosuppressed patients and after congenital infections. Therefore, development of a vaccine against HCMV is a main public health priority. Revealing the complex interaction between HCMV and host responses, is of utmost importance for understanding viral pathogenesis and for vaccine design. The present data contribute to the understanding of HCMV-specific host immune responses and reveal specifically the interaction between HLA-E and the virus-encoded UL40 peptide, which further leads to a potent NK cell response. We demonstrate that this interaction is a key factor for reduction of virus replication in immunosuppressed patients. We further show that distinct naturally occurring HCMV-UL40 variants reduce the activation of a specific subpopulation of host NK cells and thereby are associated with high-level viremia in the patients. These findings will allow the characterization of patients at risk for severe HCMV infection and contribute to strategies for HCMV vaccine development.

Viral Load Kinetics of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospitalized Individuals With Coronavirus Disease 2019.

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) kinetics remain understudied, including the impact of remdesivir. In hospitalized individuals, peak sputum viral load occurred in week 2 of symptoms, whereas viremia peaked within 1 week of symptom-onset, suggesting early systemic seeding of SARS-CoV-2. Remdesivir treatment was associated with faster viral decay.

Role of African swine fever virus (ASFV) proteins EP153R and EP402R in reducing viral persistence in blood and virulence in pigs infected with BeninΔDP148R.

Abstract: The limited knowledge on the role of many of the approximately 170 proteins encoded by African swine fever virus restricts progress towards vaccine development. Previously, the DP148R gene was deleted from the genome of genotype I virulent Benin 97/1 isolate. This virus, BeninΔDP148R, induced transient moderate clinical signs after immunization and high levels of protection against challenge. However, the BeninΔDP148R virus and genome persisted in blood over a prolonged period. In the current study deletion of either EP402R or EP153R genes individually or in combination from BeninΔDP148R genome was shown not to reduce virus replication in macrophages in vitro. However, deletion of EP402R dramatically reduced the period of infectious virus persistence in blood in immunized pigs from 28 to 14 days and virus genome from 59 to 14 days, whilst maintaining high levels of protection against challenge. The additional deletion of EP153R (BeninΔDP148RΔEP153RΔEP402R) further attenuated the virus and no viremia or clinical signs were observed post-immunization. This was associated with decreased protection and detection of moderate levels of challenge virus in blood. Interestingly, the deletion of EP153R alone from BeninΔDP148R did not result in further virus attenuation and did not reduce the period of virus persistence in blood. These results show that EP402R and EP153R have a synergistic role in reducing clinical signs and levels of virus in blood. Importance: African swine fever virus (ASFV) causes a disease of domestic pigs and wild boar which results in death of almost all infected animals. The disease has a high economic impact, and no vaccine is available. We investigated the role of two ASFV proteins, called EP402R and EP153R, in determining the levels and length of time virus persists in blood from infected pigs. EP402R causes ASFV particles and infected cells to bind to red blood cells. Deletion of the EP402R gene dramatically reduced virus persistence in blood but did not reduce the level of virus. Deletion of the EP153R alone did not reduce the period or level of virus persistence in blood. However, deleting both EP153R and EP402R resulted in undetectable levels of virus in blood and no clinical signs showing the proteins act synergistically. Importantly the infected pigs were protected following infection with the wildtype virus that kills pigs.

Stable Latent HIV Infection and Low-Level Viremia Despite Treatment with the Broadly Neutralizing Antibody VRC07-523LS and the Latency Reversal Agent Vorinostat.

Abstract: We tested the combination of a broadly neutralizing HIV antibody with the latency reversal agent vorinostat (VOR). Eight participants received two month-long cycles of VRC07-523LS with VOR. Low-level viremia, resting CD4+ T cell-associated HIV RNA (rca-RNA), intact proviral DNA assay (IPDA), and quantitative viral outgrowth assay (QVOA) were measured at baseline and post-treatment. In three participants, IPDA and QVOA declines were accompanied by significant declines of rca-RNA. However, no IPDA or QVOA declines clearly exceeded assay variance or natura decay. Increased resistance to VRC07-523LS was not observed. This combination therapy did not reduce viremia or the HIV reservoir.

Antibody-dependent enhancement representing in vitro infective progeny virus titer correlates with the viremia level in dengue patients.

Abstract: Dengue virus (DENV) causes dengue fever (DF) and dengue hemorrhagic fever in humans. Some DF patients suddenly develop severe symptoms around the defervescent period. Although the pathogenic mechanism of the severe symptoms has not been fully elucidated, the viremia level in the early phase has been shown to correlate with the disease severity. One of the hypotheses is that a phenomenon called antibody-dependent enhancement (ADE) of infection leads to high level of viremia. To examine the plausibility of this hypothesis, we examined the relationship between in vitro ADE activity and in vivo viral load quantity in six patients with dengue diseases. Blood samples were collected at multiple time points between the acute and defervescent phases, and the balance between neutralizing and enhancing activities against the autologous and prototype viruses was examined. As the antibody levels against DENV were rapidly increased, ADE activity was decreased over time or partially maintained against some viruses at low serum dilution. In addition, positive correlations were observed between ADE activity representing in vitro progeny virus production and viremia levels in patient plasma samples. The measurement of ADE activity in dengue-seropositive samples may help to predict the level of viral load in the subsequent DENV infection.

Residual Viremia Is Linked to a Specific Immune Activation Profile in HIV-1-Infected Adults Under Efficient Antiretroviral Therapy.

Abstract: Chronic immune activation persists in persons living with HIV-1 even though they are aviremic under antiretroviral therapy, and fuels comorbidities. In previous studies, we have revealed that virologic responders present distinct profiles of immune activation, and that one of these profiles is related to microbial translocation. In the present work, we tested in 140 HIV-1-infected adults under efficient treatment for a mean duration of eight years whether low-level viremia might be another cause of immune activation. We observed that the frequency of viremia between 1 and 20 HIV-1 RNA copies/mL (39.5 ± 24.7% versus 21.1 ± 22.5%, p = 0.033) and transient viremia above 20 HIV-1 RNA copies/mL (15.1 ± 16.9% versus 3.3 ± 7.2%, p = 0.005) over the 2 last years was higher in patients with one profile of immune activation, Profile E, than in the other patients. Profile E, which is different from the profile related to microbial translocation with frequent CD38+ CD8+ T cells, is characterized by a high level of CD4+ T cell (cell surface expression of CD38), monocyte (plasma concentration of soluble CD14), and endothelium (plasma concentration of soluble Endothelial Protein C Receptor) activation, whereas the other profiles presented low CD4:CD8 ratio, elevated proportions of central memory CD8+ T cells or HLA-DR+ CD4+ T cells, respectively. Our data reinforce the hypothesis that various etiological factors shape the form of the immune activation in virologic responders, resulting in specific profiles. Given the type of immune activation of Profile E, a potential causal link between low-level viremia and atherosclerosis should be investigated.