Administration of HeberFERON in Patients with Persistent Oropharyngeal SARS-CoV-2 Wuhan/D614G Strain Viral Shedding

Study background: HeberFERON accelerates SARS-CoV-2 clearance in COVID-19 cases. Considering this we evaluated the employment of HeberFERON in patients with more than 14 days of viral shedding. Methods: This is a case series study of mild or moderate ill patients with laboratory-confirmed SARS-CoV-2 from one hospital in Havana, Cuba. We evaluated the effect and safety of HeberFERON in patients previously treated with Heberon Apha R that resulted with prolonged viral shedding. All patients received lopinavir-ritonavir 200/50 mg every 12 h and chloroquine 250 mg every 12 h. The primary endpoint was the time to negativization of viral RNA in patients with persistent viral shedding. The protocol was approved by the Ethics Committee of the Luis Diaz Soto Hospital. Results: The characteristics of the individuals included the age ranged from 19-87 years with a mean of 40 years, (Study and Control I groups), while in the Control group II the mean age was 43.8 years. Leukocytes, platelets, neutrophils, and eosinophils, show a significantly lower counts in the groups with viral persistence. Under IFN treatment the median viral shedding duration from diagnosis were 21 days and 19 days in Study group and Control group II, respectively. The Control group I showed a median viral shedding of 11 days (log-rank p = 0.000). Significant longer median viral negativization time (19 days) of symptomatic than asymptomatic patients (11 days, Long-rank p = 0.004), was observed. In patients under Heberon Alpha R treatment that resulted persistent for viral presence, the median time to viral negativization was 7 days for the period of administration of HeberFERON. Being symptomatic at diagnosis was significantly associated with viral persistence. The HeberFERON showed an adequate safety profile. Conclusion: HeberFERON showed a safe and rapid negativization of patients with viral persistence, achieving negativization in more than 50% of patients in 7 days.

Pteridium spp. and Bovine Papillomavirus: Partners in Cancer

Bovine papillomavirus (BPV) are a cause for global concern due to their wide distribution and the wide range of benign and malignant diseases they are able to induce. Those lesions include cutaneous and upper digestive papillomas, multiple histological types of urinary bladder cancers—most often associated with BPV1 and BPV2—and squamous cell carcinomas of the upper digestive system, associated with BPV4. Clinical, epidemiological and experimental evidence shows that exposure to bracken fern (Pteridium spp.) and other related ferns plays an important role in allowing viral persistence and promoting the malignant transformation of early viral lesions. This carcinogenic potential has been attributed to bracken illudane glycoside compounds with immune suppressive and mutagenic properties, such as ptaquiloside. This review addresses the role of BPV in tumorigenesis and its interactions with bracken illudane glycosides. Current data indicates that inactivation of cytotoxic T lymphocytes and natural killer cells by bracken fern illudanes plays a significant role in allowing viral persistence and lesion progression, while BPV drives unchecked cell proliferation and allows the accumulation of genetic damage caused by chemical mutagens. Despite limited progress in controlling bracken infestation in pasturelands, bracken toxins remain a threat to animal health. The number of recognized BPV types has steadily increased over the years and now reaches 24 genotypes with different pathogenic properties. It remains essential to widen the available knowledge concerning BPV and its synergistic interactions with bracken chemical carcinogens, in order to achieve satisfactory control of the livestock losses they induce worldwide.

491. Persistence of SARS-CoV-2 Iinfection in Immunocompromised Children

Background The temporal dynamics of SARS-CoV-2 infectivity in immunocompromised children (IC) are unknown but may have important infection control implications. We evaluated SARS-CoV-2 viral persistence and assessed factors associated with viral persistence and cycle threshold (CT) values as a surrogate of viral load for IC. Methods We conducted a retrospective cohort study of SARS-CoV-2-positive IC at a large quaternary pediatric hospital from March 2020-2021. Immunocompromised status was defined as primary or secondary/acquired immunodeficiencies due to comorbidities or immunosuppressive treatment. The primary outcome was time to first-of-two consecutively negative SARS-CoV-2 PCR tests ≥ 24 hours apart. Polymerase chain reaction (PCR) testing of sequential patient samples was conducted using the Centers for Disease Control 2019-nCoV Real-Time RT-PCR Diagnostic Panel (CDC assay). Chi-square, Fisher exact, and Wilcoxon tests were used to compare demographic and clinical characteristics. Kaplan-Meier curve median event times and log-rank tests were used to compare outcomes. Subjects without 2 consecutive negative tests censored at the last test. Analyses were conducted using SAS v 9.4. Results Ninety-one children met inclusion criteria, and 67 children had more than 1 test (Figure 1). Median age was 15.5 years (IQR 8-18 yrs), 64% were male, 58% of children were white, and 43% were Latinx. Most (67%) were tested in outpatient settings, and 58% of children were asymptomatic. The median time to two negative tests was 42 days (IQR 25.0,55.0), with no difference in duration of positivity with specific diagnoses, degree of lymphopenia, or symptomatic vs asymptomatic illness. Five of 7 (71%) children with samples available for repeat testing had initial CT values < 30, indicating a moderate to high viral load, and of these, 4 (57%) had repeat testing 21 to 30 days later with CT values < 30 (Figure 2), suggesting persistence of moderate to high viral loads. Figure 1. Plot of immunocompromised children in cohort with positive SARS CoV2 PCR and subsequent testing (n = 67). Timelines of immunocompromised children in cohort with positive SARS CoV2 PCR and subsequent testing, grouped by immunocompromising condition. Each line represents an individual patient. Positive results are shown in light grey, negative results are shown in black. Figure 2. Plot of CT values from SARS-CoV-2 PCR testing over time among children with sequential samples available for retesting (n = 7) Plot of CT values (y axis) from SARS-CoV-2 PCR testing on the CDC assay over time (x axis) in days from initial positive test. Repeated testing which yielded a negative result on the CDC assay or intermittent negative results on clinical testing represented as CT value of 40. Each line represents a unique patient. Conclusion The median duration of viral persistence among IC with SARS-CoV-2 infection was 6 weeks, with no significant difference in immunocompromised diagnoses or clinical presentation, with over half of children with testing on the same platform having moderate to high viral loads after 3 weeks, suggesting potential transmission risk. Disclosures Samuel R. Dominguez, MD, PhD, BioFire Diagnostics (Consultant, Research Grant or Support)DiaSorin Molecular (Consultant)Pfizer (Grant/Research Support) Samuel R. Dominguez, MD, PhD, BioFire (Individual(s) Involved: Self): Consultant, Research Grant or Support; DiaSorin Molecular (Individual(s) Involved: Self): Consultant; Pfizer (Individual(s) Involved: Self): Grant/Research Support Suchitra Rao, MBBS, MSCS, BioFire (Research Grant or Support)

Sequencing Directly from Clinical Specimens Reveals Genetic Variations in HCMV-Encoded Chemokine Receptor US28 That May Influence Antibody Levels and Interactions with Human Chemokines

Human cytomegalovirus (HCMV) is a common viral pathogen of solid organ transplant recipients, neonates, and HIV-infected individuals. HCMV encodes homologs of several host genes with the potential to influence viral persistence and/or pathogenesis.

Uncertainty around the Long-Term Implications of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 231 million people globally, with more than 4.7 million deaths recorded by the World Health Organization as of 26 September 2021. In response to the pandemic, some countries (New Zealand, Vietnam, Taiwan, South Korea and others) have pursued suppression strategies, so-called Zero COVID policies, to drive and maintain infection rates as close to zero as possible and respond aggressively to new cases. In comparison, European countries and North America have adopted mitigation strategies (of varying intensity and effectiveness) that aim primarily to prevent health systems from being overwhelmed. With recent advances in our understanding of SARS-CoV-2 and its biology, and the increasing recognition there is more to COVID-19 beyond the acute infection, we offer a perspective on some of the long-term risks of mutational escape, viral persistence, reinfection, immune dysregulation and neurological and multi-system complications (Long COVID).

Chronic LCMV Infection Is Fortified with Versatile Tactics to Suppress Host T Cell Immunity and Establish Viral Persistence

Ever since the immune regulatory strains of lymphocytic choriomeningitis virus (LCMV), such as Clone 13, were isolated, LCMV infection of mice has served as a valuable model for the mechanistic study of viral immune suppression and virus persistence. The exhaustion of virus-specific T cells was demonstrated during LCMV infection, and the underlying mechanisms have been extensively investigated using LCMV infection in mouse models. In particular, the mechanism for gradual CD8+ T cell exhaustion at molecular and transcriptional levels has been investigated. These studies revealed crucial roles for inhibitory receptors, surface markers, regulatory cytokines, and transcription factors, including PD-1, PSGL-1, CXCR5, and TOX in the regulation of T cells. However, the action mode for CD4+ T cell suppression is largely unknown. Recently, sphingosine kinase 2 was proven to specifically repress CD4+ T cell proliferation and lead to LCMV persistence. As CD4+ T cell regulation was also known to be important for viral persistence, research to uncover the mechanism for CD4+ T cell repression could help us better understand how viruses launch and prolong their persistence. This review summarizes discoveries derived from the study of LCMV in regard to the mechanisms for T cell suppression and approaches for the termination of viral persistence with special emphasis on CD8+ T cells.

SARS-CoV-2 surrogate (Phi6) environmental persistence within free-living amoebae

The reported persistence of SARS-CoV-2 virions in aquatic environments highlights the need to better understand potential mechanisms that may prolong its dissemination. We evaluated the possibility that amoebae might serve as transport hosts by studying the interaction of the enveloped bacteriophage Phi6, as a potential surrogated along with one of the most common amoebae in engineered aquatic environments, Vermamoeba vermiformis. Using microscopy, imaging flow cytometry and bacteriophage cell culture, our results imply that the SARS-CoV-2 surrogate triggers amoebic mitochondria and induced apoptosis to promote viral persistence in trophozoites. Furthermore, virus-infected amoebae were still infectious after 2 months within FLA cysts. These results suggest that amoebae could contribute to the environmental persistence of SARS-CoV-2, including disinfection processes. In addition, amoebae could be a successful model system for understanding respiratory virus-eukaryotic biology at the cellular and molecular levels.

The Functions of Hepatitis B Virus Encoding Proteins: Viral Persistence and Liver Pathogenesis

About 250 million people worldwide are chronically infected with Hepatitis B virus (HBV), contributing to a large burden on public health. Despite the existence of vaccines and antiviral drugs to prevent infection and suppress viral replication respectively, chronic hepatitis B (CHB) cure remains a remote treatment goal. The viral persistence caused by HBV is account for the chronic infection which increases the risk for developing liver cirrhosis and hepatocellular carcinoma (HCC). HBV virion utilizes various strategies to escape surveillance of host immune system therefore enhancing its replication, while the precise mechanisms involved remain elusive. Accumulating evidence suggests that the proteins encoded by HBV (hepatitis B surface antigen, hepatitis B core antigen, hepatitis B envelope antigen, HBx and polymerase) play an important role in viral persistence and liver pathogenesis. This review summarizes the major findings in functions of HBV encoding proteins, illustrating how these proteins affect hepatocytes and the immune system, which may open new venues for CHB therapies.