Cross-reactivity of hantavirus antibodies after immunization with PUUV antigens.

Nephropathia epidemica (NE), caused by Puumala (PUUV) orthohantavirus, is endemic in the Republic of Tatarstan (RT). There are limited options for NE prevention in RT. Currently, available vaccines are made using Haantan (HNTV) orthohantavirus antigens. In this study, the efficacy of microvesicles (MVs) loaded with PUUV antigens to induce the humoral immune response in small mammals was analyzed. Additionally, the cross-reactivity of serum from immunized small mammals and NE patients with HNTV, Dobrava, and Andes orthohantaviruses was investigated using nucleocapsid (N) protein peptide libraries. Finally, the selected peptides were analyzed for allergenicity, their ability to induce an autoimmune response, and their interaction with Class II HLA. Several N protein peptides were found to be cross-reactive with serum from MVs immunized small mammals. These cross-reactive epitopes were located in oligomerization perinuclear targeting and Daxx-interacting domains. Most cross-reactive peptides lack allergenic and autoimmune reactivity. Molecular docking revealed two cross-reacting peptides, N6 and N19, to have good binding with three Class II HLA alleles. These peptides could be candidates for developing vaccines and therapeutics for NE.

Neutralizing Antibodies in COVID-19 Serum from Tatarstan, Russia.

The severity of COVID-19 is a result of the complex interplay between various branches of the immune system. However, our understanding of the role of neutralizing antibodies and the activation of cellular immune response in COVID-19 pathogenesis remains limited. In this study, we investigated neutralizing antibodies in patients with mild, moderate, and severe COVID-19, analyzing their cross-reactivity with the Wuhan and Omicron variants. We also assessed the activation of the immune response by measuring serum cytokines in patients with mild, moderate, and severe COVID-19. Our findings suggest the early activation of neutralizing antibodies in moderate COVID-19 compared to mild cases. We also observed a strong correlation between the cross-reactivity of neutralizing antibodies to the Omicron and Wuhan variants and the severity of the disease. In addition, we found that Th1 lymphocyte activation was present in mild and moderate cases, while inflammasomes and Th17 lymphocytes were activated in severe COVID-19. In conclusion, our data indicate that the early activation of neutralizing antibodies is evident in moderate COVID-19, and there is a strong correlation between the cross-reactivity of neutralizing antibodies and the severity of the disease. Our findings suggest that the Th1 immune response may play a protective role, while inflammasome and Th17 activation may be involved in severe COVID-19.

Phase 3 trial to evaluate the safety, tolerability, and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine, followed by 23-valent pneumococcal polysaccharide vaccine 6 months later, in at-risk adults 18-49 years of age (PNEU-DAY): A subgroup analysis by baseline risk factors.

Immunocompetent adults with certain medical and behavioral factors are at increased risk of pneumococcal disease. In some countries, sequential vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for at-risk adults. This subgroup analysis from a phase 3 study evaluated the safety, tolerability, and immunogenicity of sequential administration of either V114 (a 15-valent PCV containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F) or PCV13, followed 6 months later by PPSV23, in immunocompetent adults 18-49 years of age with pre-defined risk factors for pneumococcal disease. Safety and immunogenicity post-vaccination were analyzed by type and baseline number of risk factors for pneumococcal disease (1 and ≥2 risk factors). This analysis included 1,131 participants randomized 3:1 to receive either V114 or PCV13, followed by PPSV23. The majority (73.1%) of participants had at least one risk factor. Safety and tolerability profiles of V114 and PCV13 were similar across risk factor groups. V114 administered either alone or sequentially with PPSV23 6 months later was immunogenic for all 15 serotypes, including those not contained in PCV13, regardless of the number of baseline risk factors. V114 has the potential to broaden serotype coverage for at-risk adults.

Molnupiravir for the treatment of COVID-19 in immunocompromised participants: efficacy, safety, and virology results from the phase 3 randomized, placebo-controlled MOVe-OUT trial.

PURPOSE: Immunocompromised patients have a potentially increased risk for progression to severe COVID-19 and prolonged replication of SARS-CoV-2. This post hoc analysis examined outcomes among immunocompromised participants in the MOVe-OUT trial. METHODS: In phase 3 of MOVe-OUT, non-hospitalized at-risk adults with mild-to-moderate COVID-19 were randomized to receive molnupiravir 800 mg or placebo twice daily for 5 days. Immunocompromised participants were identified based on prior/concomitant medications and/or medical history. All-cause hospitalization/death, adverse events, SARS-CoV-2 titers, infectivity, and RNA sequences were compared between immunocompromised participants who received molnupiravir or placebo and with non-immunocompromised participants. RESULTS: Fifty-five of 1408 participants were considered immunocompromised. Compared to placebo, fewer molnupiravir-treated immunocompromised participants were hospitalized/died through Day 29 (22.6% [7/31] vs. 8.3% [2/24]), with fewer adverse events (45.2% [14/31] vs. 25.0% [6/24]). A larger mean change from baseline in SARS-CoV-2 RNA was observed with molnupiravir compared to placebo in non-immunocompromised participants (least squares mean [LSM] difference Day 5: - 0.31, 95% confidence interval [CI] - 0.47 to - 0.15), while the mean change was comparable between treatment groups in immunocompromised participants (LSM difference Day 5: 0.23, 95% CI - 0.71 to 1.17). Molnupiravir treatment was associated with increased clearance of infectious virus. Increased errors in viral nucleotide sequences in post-baseline samples compared to placebo support molnupiravir's mechanism of action and were not associated with observation of novel treatment-emergent amino acid substitutions in immunocompromised participants. CONCLUSION: Although the study population was small, these data suggest that molnupiravir treatment for mild-to-moderate COVID-19 in non-hospitalized immunocompromised adults is efficacious and safe and quickly reduces infectious SARS-CoV-2. GOV REGISTRATION NUMBER: NCT04575597.

Safety and efficacy of bulevirtide in combination with tenofovir disoproxil fumarate in patients with hepatitis B virus and hepatitis D virus coinfection (MYR202): a multicentre, randomised, parallel-group, open-label, phase 2 trial.

BACKGROUND: Bulevirtide is a first-in-class peptidic entry inhibitor for hepatitis B virus (HBV) and hepatitis D virus infection. In July, 2020, bulevirtide 2 mg received conditional marketing authorisation by the European Medical Agency for treatment of chronic hepatitis D virus infection. We investigated the antiviral activity of bulevirtide in patients chronically infected with HBV and hepatitis D virus. METHODS: MYR202 (ClinicalTrials.gov, NCT03546621; EudraCT, 2016-000395-13) was a multicentre, parallel-group, randomised, open-label, phase 2 trial. Adults (aged 18-65 years) with chronic hepatitis D virus infection, including patients with cirrhosis and patients who had contraindications to PegIFNα treatment or for whom treatment did not work, were eligible and were enrolled from four hospitals in Germany and 12 hospitals in Russia. Patients were randomly assigned (1:1:1:1) to receive 2 mg (n=28), 5 mg (n=32), or 10 mg (n=30) subcutaneous bulevirtide once per day with tenofovir disoproxil fumarate (TDF; 245 mg once per day orally) or TDF alone (245 mg once per day orally; n=30) for 24 weeks. Randomisation was done using a digital block scheme with stratification, consisting of 480 randomisation numbers separated into 30 blocks. The primary endpoint was undetectable hepatitis D virus RNA or 2 log10 IU/mL or higher decline in hepatitis D virus RNA at week 24, which was analysed in the modified intention-to-treat population, including patients who received study medication at least once after randomisation. Hepatitis D virus RNA concentrations were monitored until week 48. Safety was assessed for all patients who received at least one dose of bulevirtide or TDF. FINDINGS: Between Feb 16, 2016, and Dec 8, 2016, 171 patients with chronic hepatitis D virus infection were screened; 51 were ineligible based on the exclusion criteria and 120 patients (59 with cirrhosis) were enrolled. At week 24, 15 (54%, 95% CI 34-73) of 28 patients achieved undetectable hepatitis D virus RNA or a 2 log10 IU/mL or more decline in hepatitis D virus RNA (p<0·0001 vs TDF alone) with 2 mg bulevirtide, 16 (50%, 32-68) of 32 with 5 mg bulevirtide (p<0·0001), and 23 (77%, 58-90) of 30 with 10 mg bulevirtide (p<0·0001), versus one (4%, 0·1-18) of 28 with TDF alone. By week 48 (24 weeks after bulevirtide cessation), hepatitis D virus RNA concentrations had rebounded, with median changes from week 24 to week 48 of 1·923 log10 IU/mL (IQR 0·566-2·485) with 2 mg bulevirtide, 1·732 log10 (0·469-2·568) with 5 mg bulevirtide, and 2·030 log10 (1·262-2·903) with 10 mg bulevirtide. There were no deaths associated with treatment. Three (9%) patients in the bulevirtide 5 mg group, two (7%) patients in the bulevirtide 10 mg group, and one (4%) patient in the TDF group had serious adverse events. Common treatment-emergent adverse events included asymptomatic bile salt increases and increases in alanine aminotransferase and aspartate aminotransferase. INTERPRETATION: Bulevirtide induced a significant decline in hepatitis D virus RNA over 24 weeks. After cessation of bulevirtide, hepatitis D virus RNA concentrations rebounded. Longer treatment durations and combination therapies should be investigated. FUNDING: Hepatera LLC, MYR GmbH, and the German Centre for Infection Research, TTU Hepatitis.

Antibody and T Cell Immune Responses to SARS-CoV-2 Peptides in COVID-19 Convalescent Patients.

Identifying immunogenic targets of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is critical to advance diagnostic and disease control strategies. We analyzed humoral (ELISA) and T-cell (ELISpot) immune responses to spike (S) and nucleocapsid (N) SARS-CoV-2 proteins as well as to human endemic coronavirus (eCoV) peptides in serum from convalescent coronavirus disease 2019 (COVID-19) patients from Tatarstan, Russia. We identified multiple SARS-CoV-2 peptides that were reactive with serum antibodies and T cells from convalescent COVID-19. In addition, age and gender associated differences in the reactivity to S and N protein peptides were identified. Moreover, several SARS-CoV-2 peptides tested negatively correlated with disease severity and lung damage. Cross-reactivity to eCoV peptides was analyzed and found to be lower in COVID-19 compared to controls. In this study, we demonstrate the changing pattern of immunogenic peptide reactivity in COVID-19 serum based on age, gender and previous exposure to eCoVs. These data highlight how humoral immune responses and cytotoxic T cell responses to some of these peptides could contribute to SARS-CoV-2 pathogenesis.

Immunogenicity, Safety, and Tolerability of V114, a 15-Valent Pneumococcal Conjugate Vaccine, in Immunocompetent Adults Aged 18-49 Years With or Without Risk Factors for Pneumococcal Disease: A Randomized Phase 3 Trial (PNEU-DAY).

BACKGROUND: Adults with certain medical and behavioral factors are at increased risk for pneumococcal disease (PD). Sequential vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for at-risk adults in some countries. METHODS: This phase 3 trial evaluated the safety, tolerability, and immunogenicity of sequential administration of either V114 (a 15-valent PCV containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F) or PCV13, followed 6 months later by PPSV23, in immunocompetent adults aged 18-49 years with or without predefined risk factors for PD (NCT03547167). Overall, 1515 participants were randomized 3:1 to receive either V114 or PCV13, followed by PPSV23. RESULTS: Most common solicited adverse events (AEs) following administration of V114 or PCV13 as well as PPSV23 were injection-site pain and fatigue. The proportion of participants with AEs was comparable in both groups. V114 and PCV13 were immunogenic based on opsonophagocytic activity (OPA) geometric mean titers (GMTs) 30 days postvaccination for all serotypes contained in each respective vaccine. OPA GMTs to the 2 unique serotypes in V114 were robust in the V114 group. PPSV23 was immunogenic for all 15 serotypes contained in V114 in both vaccination groups, including 22F and 33F. CONCLUSIONS: V114 administered alone or sequentially with PPSV23 is well tolerated and immunogenic for all 15 serotypes, including those not contained in PCV13, in immunocompetent adults aged 18-49 years with or without certain medical or behavioral risk factors for PD. CLINICAL TRIALS REGISTRATION: NCT03547167 and EudraCT 2017-004915-38.

Randomized Trial of Molnupiravir or Placebo in Patients Hospitalized with Covid-19.

BACKGROUND: Molnupiravir is an oral prodrug of ß-D-N4-hydroxycytidine, active against SARS-CoV-2 in vitro and in animal models. We report data from the phase 2 component of MOVe-IN, a clinical trial evaluating molnupiravir in patients hospitalized with Covid-19. METHODS: We conducted a randomized, placebo-controlled, double-blind phase 2/3 trial in patients 18 years old and older requiring in-hospital treatment for laboratory-confirmed Covid-19 with symptom onset 10 or fewer days before randomization. Participants were randomly assigned to placebo or molnupiravir 200 mg, 400 mg, or 800 mg (1:1:1:1 ratio), twice daily for 5 days. Primary end points were safety and sustained recovery (participant alive and either not hospitalized or medically ready for discharge) through day 29. RESULTS: Of 304 randomly assigned participants, 218 received at least one dose of molnupiravir and 75 of placebo. At baseline, 74.0% had at least one risk factor for severe Covid-19. Adverse events were reported in 121 of 218 (55.5%) molnupiravir-treated and 46 of 75 (61.3%) placebo-treated participants, with no apparent dose effect on adverse event rates and no evidence of hematologic toxicity based on prespecified adverse events. Of 16 confirmed deaths, most were in participants with severe Covid-19 (75.0%), with underlying comorbidities (87.5%), older than 60 years of age (81.3%), and/or symptom duration longer than 5 days (75.0%) at randomization. Median time to sustained recovery was 9 days in all groups, with similar day 29 recovery rates ranging from 81.5% to 85.2%. CONCLUSIONS: In this phase 2 trial of patients hospitalized with Covid-19, a 5-day course of molnupiravir up to 800 mg twice daily was not associated with dose-limiting side effects or adverse events, but did not demonstrate clinical benefit. (Funded by Merck Sharp & Dohme; ClinicalTrials.gov NCT04575584.)

Long Term Immune Response Produced by the SputnikV Vaccine.

SputnikV is a vaccine against SARS-CoV-2 developed by the Gamaleya National Research Centre for Epidemiology and Microbiology. The vaccine has been shown to induce both humoral and cellular immune responses, yet the mechanisms remain largely unknown. Forty SputnikV vaccinated individuals were included in this study which aimed to demonstrate the location of immunogenic domains of the SARS-CoV-2 S protein using an overlapping peptide library. Additionally, cytokines in the serum of vaccinated and convalescent COVID-19 patients were analyzed. We have found antibodies from both vaccinated and convalescent sera bind to immunogenic regions located in multiple domains of SARS-CoV-2 S protein, including Receptor Binding Domain (RBD), N-terminal Domain (NTD), Fusion Protein (FP) and Heptad Repeats (HRs). Interestingly, many peptides were recognized by immunized and convalescent serum antibodies and correspond to conserved regions in circulating variants of SARS-CoV-2. This breadth of reactivity was still evident 90 days after the first dose of the vaccine, showing that the vaccine has induced a prolonged response. As evidenced by the activation of T cells, cellular immunity strongly suggests the high potency of the SputnikV vaccine against SARS-CoV-2 infection.

Characterization of the Puumala orthohantavirus Strains in the Northwestern Region of the Republic of Tatarstan in Relation to the Clinical Manifestations in Hemorrhagic Fever With Renal Syndrome Patients.

Over 1,000 cases of hemorrhagic fever with renal syndrome (HFRS) were recorded in the Republic of Tatarstan (RT) in 2015. HFRS is a zoonotic disease caused by several different Old World hantaviruses. In RT, Puumala orthohantavirus (PUUV) is a prevalent etiological agent of HFRS. We looked for the genetic link between the PUUV strains isolated from the bank voles and from the infected humans. In addition, possible correlation between the genetic makeup of the PUUV strain involved and different clinical picture of HFRS was investigated. Partial PUUV small (S) genome segment sequences were retrieved from 37 small animals captured in the northwestern region of RT in 2015. Phylogenetic analysis revealed that 34 PUUV sequences clustered with strains of the previously identified "Russia" (RUS) genetic lineage, while 3 remaining PUUV sequences clustered with the known lineage from Finland (FIN). Sequence comparisons showed that the majority of the S-segment sequences isolated in the current study displayed 98.2-100.0% sequence identity when compared with the strains isolated earlier from the HFRS patients hospitalized in Kazan city. HFRS patients infected with PUUV strains of either RUS or FIN genetic lineages were observed to have consistent differences in clinical presentation of the disease and laboratory findings. These findings indicated a strong genetic link between the infected bank voles and human HFRS cases from the same localities. Thus, S-segment sequences of the PUUV strains isolated from HFRS patients could serve as a molecular marker for determining the likely geographic area where infection occurred.

Δccr5 Genotype Is Associated with Mild Form of Nephropathia Epidemica.

Nephropathia Epidemica (NE), a mild form of hemorrhagic fever with renal syndrome (HFRS) and linked to hantavirus infection, is endemic in the Republic of Tatarstan. Several genetic markers of HFRS severity have been identified previously, including human leukocyte antigen (HLA) complexes and nucleotide polymorphism in the tumor necrosis factor alpha (TNFα) gene. Still, our understanding of the genetic markers of NE severity remains incomplete. The frequency of the C-C chemokine receptor type 5 (CCR5) gene wild type and gene with 32-base-pair deletion (Δ32CCR5) genotypes in 98 NE samples and 592 controls was analyzed using PCR. Along with the serum levels of 94 analytes, a lack of differences in the CCR5 genotype distribution between NE cases and the general population suggests that the CCR5 genotype does not affect susceptibility to hantavirus infection. However, in NE cases, significant variation in the serum levels of the host matrix metalloproteases between functional CCR5 homozygous and Δ32CCR5 heterozygous patients was detected. Also, the oliguric phase was longer, while thrombocyte counts were lower in functional CCR5 homozygous as compared to heterozygous NE cases. Our data, for the first time, presents the potential role of the CCR5 receptor genotype in NE pathogenesis. Our data suggests that NE pathogenesis in functional CCR5 homozygous and heterozygous NE patients differs, where homozygous cases may have more disintegration of the extracellular matrix and potentially more severe disease.

Urinary Clusterin Is Upregulated in Nephropathia Epidemica.

Kidney insufficiency is a hallmark of nephropathia epidemica (NE). Little is known about the mechanisms of the NE kidney pathology, with current knowledge mainly based on findings in postmortem tissue. We have analyzed kidney damage biomarkers in urine collected from early- and late-phase NE using Bio-Plex kidney toxicity panels 1 and 2. To determine the disease specificity, kidney damage biomarkers were also analyzed in urine samples from patients diagnosed with gout, type 2 diabetes, systemic lupus erythematosus, and chronic kidney insufficiency. Analysis of 12 biomarkers suggests damage to the kidney proximal tubule at the onset of NE. Also, upregulation of biomarkers of inflammation and leukocyte chemotaxis were detected in NE urine. Furthermore, increased clusterin levels were found in early- and late-phase NE urine. Comparative analysis revealed that clusterin is a biomarker, upregulated in NE urine.

High Triglycerides Are Associated with Low Thrombocyte Counts and High VEGF in Nephropathia Epidemica.

Nephropathia epidemica (NE) is a mild form of hemorrhagic fever with renal syndrome. Several reports have demonstrated a severe alteration in lipoprotein metabolism. However, little is known about changes in circulating lipids in NE. The objectives of this study were to evaluate changes in serum total cholesterol, high density cholesterol (HDCL), and triglycerides. In addition to evaluation of serum cytokine activation associations, changes in lipid profile and cytokine activation were determined for gender, thrombocyte counts, and VEGF. Elevated levels of triglycerides and decreased HDCL were observed in NE, while total cholesterol did not differ from controls. High triglycerides were associated with both the lowest thrombocyte counts and high serum VEGF, as well as a high severity score. Additionally, there were higher levels of triglycerides in male than female NE patients. Low triglycerides were associated with upregulation of IFN-γ and IL-12, suggesting activation of Th1 helper cells. Furthermore, levels of IFN-γ and IL-12 were increased in patients with lower severity scores, suggesting that a Th1 type immune response is playing protective role in NE. These combined data advance the understanding of NE pathogenesis and indicate a role for high triglycerides in disease severity.