Efficacy and immunogenicity following dengue virus-1 human challenge after a tetravalent prime-boost dengue vaccine regimen: an open-label, phase 1 trial.

BACKGROUND: Dengue human infection models (DHIMs) are important tools to down-select dengue vaccine candidates and establish tetravalent efficacy before advanced clinical field trials. We aimed to provide data for the safety and immunogenicity of DHIM and evaluate dengue vaccine efficacy. METHODS: We performed an open-label, phase 1 trial at the University of Maryland (Baltimore, MD, USA). Eligible participants were healthy individuals aged 18-50 years who either previously received a tetravalent dengue purified inactivated vaccine prime followed by a live-attenuated vaccine boost (ie, the vaccinee group), or were unvaccinated flavivirus-naive participants (ie, the control group). Participants in the vaccinee group with detectable pre-challenge dengue virus-1 neutralising antibody titres and flavivirus-naive participants in the control group were inoculated with dengue virus-1 strain 45AZ5 in the deltoid region, 27-65 months following booster dosing. These participants were followed-up from days 4-16 following dengue virus-1 live virus human challenge, with daily real-time quantitative PCR specific to dengue virus-1 RNA detection, and dengue virus-1 solicited local and systemic adverse events were recorded. The primary outcomes were safety (ie, solicited local and systemic adverse events) and vaccine efficacy (ie, dengue virus-1 RNAaemia) following dengue challenge. This study is registered with ClinicalTrials.gov, number NCT04786457. FINDINGS: In January 2021, ten eligible participants were enrolled; of whom, six (60%) were in the vaccinee group and four (40%) were in the control group. Daily quantitative PCR detected dengue virus-1 RNA in nine (90%) of ten participants (five [83%] of six in the vaccinee group and all four [100%] in the control group). The mean onset of RNAaemia occurred on day 5 (SD 1·0) in the vaccinee group versus day 8 (1·5) in the control group (95% CI 1·1-4·9; p=0·007), with a trend towards reduced RNAaemia duration in the vaccinee group compared with the control group (8·2 days vs 10·5 days; 95% CI -0·08 to 4·68; p=0·056). Mild-to-moderate symptoms (nine [90%] of ten), leukopenia (eight [89%] of nine), and elevated aminotransferases (seven [78%] of nine) were commonly observed. Severe adverse events were detected only in the vaccinee group (fever ≥38·9°C in three [50%] of six, headache in one [17%], and transient grade 4 aspartate aminotransferase elevation in one [17%]). No deaths were reported. INTERPRETATION: Participants who had tetravalent dengue purified inactivated vaccine prime and live-attenuated vaccine boost were unprotected against dengue virus-1 infection and further showed increased clinical, immunological, and transcriptomic evidence for inflammation potentially mediated by pre-existing infection-enhancing antibodies. This study highlights the impact of small cohort, human challenge models studying dengue pathogenesis and downstream vaccine development. FUNDING: Military Infectious Disease Research Program and Medical Technology Enterprise Consortium and Advanced Technology International.

RNA Interference Therapeutics for Chronic Hepatitis B: Progress, Challenges, and Future Prospects.

Chronic hepatitis B (CHB) is a global health challenge that can result in significant liver-related morbidity and mortality. Despite a prophylactic vaccine being available, patients already living with CHB often must engage in lifelong therapy with nucleoside analogues. However, the potential of RNA interference (RNAi) therapeutics as a promising avenue for CHB treatment is being explored. RNAi, particularly using small interfering RNA (siRNA), targets viral RNA that can be used to inhibit hepatitis B virus (HBV) replication. Several candidates are currently being studied and have exhibited varying success in reducing hepatitis B surface antigen (HBsAg) levels, with some showing sustained HBsAg loss after cessation of therapy. The dynamic evolution of RNAi therapy presents a promising trajectory for the development of effective and sustained treatments for CHB. This review highlights recent findings on RNAi therapeutics, including modifications for stability, various delivery vectors, and specific candidates currently in development.

A rare case of Sphingomonas paucimobilis ventriculitis.

Introduction: Nosocomial ventriculitis is a severe infection that habitually plagues neurological intensive care units. It is usually associated with external ventricular drains. Unfortunately, classic cerebral spinal fluid parameters are less specific and sensitive compared to community acquired meningitis. This is in part secondary to indolent bacteria commonly infecting external ventricular drains leading to ventriculitis. Case report: Herein, a rare case of Sphingomonas paucimobilis ventriculitis in an immunocompetent host is reported. The patient had classic symptoms of ventriculitis, but her cerebral spinal fluid parameters were benign and initial cultures were negative. Consequently, treatment was tailored to an assumed respiratory infection only to have recurrence of her symptoms. Repeat analysis of her cerebral spinal fluid was again benign, but her cerebral spinal fluid culture grew S. paucimobilis. Subsequently, the patient was treated with cefepime, which resolved her symptoms. She completed a two-week course and has had no recurrence of her infection. Conclusions: This case reinforces the need for clinicians to have heightened awareness of this emerging pathogen, its antibiotic resistance patterns, and the unique composition of this bacterium's cell wall which has ramifications on disease presentation.

Increased risk of severe COVID-19 in pregnancy in a multicenter propensity score-matched study.

OBJECTIVES: To explore the association between COVID-19 severity and pregnancy using measures such as COVID-19 ordinal scale severity score, hospitalization, intensive care unit (ICU) admission, oxygen supplementation, invasive mechanical ventilation, and death. METHODS: We conducted a retrospective, multicenter cohort study to understand the association between COVID-19 severity and pregnancy. We reviewed consecutive charts of adult females, ages 18-45, with laboratory testing for SARS-CoV-2 infection between March 1, 2020, and August 31, 2020. Cases were patients diagnosed with COVID-19 during pregnancy, whereas controls were not pregnant at the time of COVID-19 diagnosis. Primary endpoints were the COVID-19 severity score at presentation (within four hours) and the nadir of the clinical course. The secondary endpoints were the proportion of patients requiring hospitalization, ICU admission, oxygen supplementation, invasive mechanical ventilation, and death. RESULTS: A higher proportion of pregnant women had moderate to severe COVID-19 disease at the nadir of the clinical course than non-pregnant women (25 vs. 16.1 %, p=0.04, respectively). There was a higher rate of hospitalization (25.6 vs. 17.2 %), ICU admission (8.9 vs. 4.4 %), need for vasoactive substances (5.0 vs. 2.8 %), and invasive mechanical ventilation (5.6 vs. 2.8 %) in the pregnant cohort. These differences were not significant after applying propensity score matching.We found a high rate of pregnancy complications in our population (40.7 %). The most worrisome is the rate of hypertensive disorders of pregnancy (20.1 %). CONCLUSIONS: In our propensity score-matched study, COVID-19 in pregnancy is associated with an increased risk of disease severity and pregnancy complications.

A Comparison of Lymphoid and Myeloid Cells Derived from Human Hematopoietic Stem Cells Xenografted into NOD-Derived Mouse Strains.

Humanized mice are an invaluable tool for investigating human diseases such as cancer, infectious diseases, and graft-versus-host disease (GvHD). However, it is crucial to understand the strengths and limitations of humanized mice and select the most appropriate model. In this study, we describe the development of the human lymphoid and myeloid lineages using a flow cytometric analysis in four humanized mouse models derived from NOD mice xenotransplanted with CD34+ fetal cord blood from a single donor. Our results showed that all murine strains sustained human immune cells within a proinflammatory environment induced by GvHD. However, the Hu-SGM3 model consistently generated higher numbers of human T cells, monocytes, dendritic cells, mast cells, and megakaryocytes, and a low number of circulating platelets showing an activated profile when compared with the other murine strains. The hu-NOG-EXL model had a similar cell development profile but a higher number of circulating platelets with an inactivated state, and the hu-NSG and hu-NCG developed low frequencies of immune cells compared with the other models. Interestingly, only the hu-SGM3 and hu-EXL models developed mast cells. In conclusion, our findings highlight the importance of selecting the appropriate humanized mouse model for specific research questions, considering the strengths and limitations of each model and the immune cell populations of interest.

Blockade of CCR4 breaks immune tolerance in chronic hepatitis B patients by modulating regulatory pathways.

BACKGROUND: Immunotargets including checkpoint inhibitors and toll-like receptor 8 agonists have recently gained attention for the recovery of hepatitis B virus (HBV)-specific T cell exhaustion in chronic hepatitis B(CHB). Chemokine receptors have a similar significant role during viral infections; however, their role in CHB remains poorly understood. Therefore, in this study we evaluated the role of chemokine receptor 4 (CCR4) in deriving immunosuppression during CHB. METHODS: We characterized CCR4+CD8+ T cells in CHB and identified their involvement in immunosuppression. Further, we examined if CCR4 blockade with mogamulizumab antibody can recover the functional exhaustion in HBsAg-specific T cells. RESULTS: CHB patients exhibit higher frequency of CCR4+CD8+ T cells that increase with higher HBsAg levels and fibrosis scores. In vitro, HBs antigen triggers CCR4 expression. These cells express multiple inhibitory receptors and exhibit immunosuppressive functions by producing excessive immunoregulatory cytokines IL-4, IL-5, IL-10 and TGF-ß1. CCR4 Blockade significantly boosted HBsAg-specific antiviral-cytokine production(IFN-γ, TNF-α and IL-21) in T cells through enhancing their proliferation capacity and polarizing these cells towards T helper 1(Th1) and T follicular helper cells(TFH) in case of CD4 cells, and cytotoxic T cell 1(TC1) and cytotoxic T follicular(TCF) cells in case of CD8. Cytotoxic potential was improved, while no induction of immunosuppressive-cytokines was seen after anti-CCR4 treatment thereby eliminating the risk of treatment-induced immunosuppression. CCR4 blockade inhibited the development and effector function of Tregs by controlling their expansion and TGF-ß1 production preventing Tregs-induced immunotolearance. CONCLUSIONS: CCR4 blockade reconstitutes antiviral immune response in T cells and limits the immunosuppressive functions of Tregs, representing them as a promising immunotherapeutic target for functional cure of CHB.

COVID-19 Vaccines-All You Want to Know.

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pandemic has led to an unprecedented public health crisis. The collective global response has led to production of multiple safe and effective vaccines utilizing novel platforms to combat the virus that have propelled the field of vaccinology forward. Significant challenges to universal vaccine effectiveness remain, including immune evasion by SARS-CoV-2 variants, waning of immune response, inadequate knowledge of correlates of protection, and dosing in special populations. This review serves as a detailed evaluation of the development of the current SARS-CoV-2 vaccines, their effectiveness, and challenges to their deployment as a preventive tool.

A Phase 2 open label study of ledipasvir/sofosbuvir for 12 weeks in subjects with hepatitis B virus infection.

Retrospective data showed that when we administered ledipasvir/sofosbuvir (LDV/SOF) to patients with hepatitis B and C coinfection, there was a modest reduction in hepatitis B surface antigen (HBsAg). Therefore, we hypothesize that similar HBsAg reduction can be seen in hepatitis B virus (HBV) monoinfected subjects. Primary and secondary efficacy endpoints are the decline in HBsAg and HBV DNA at Week 12 from baseline, respectively. We conducted an open-label Phase 2 pilot study to evaluate the safety, tolerability, and antiviral activity of LDV and/or SOF for HBV. Eligible subjects were either suppressed on antivirals (Group B) or inactive chronic HBV (Group A, C, D). Group A and B received LDV/SOF. Group C and D received SOF 400 mg and LDV 90 mg, respectively. All subjects completed the study, and all related adverse events (AEs) were mild. No discontinuations due to AEs or hepatitis flare occurred. At Week 12, HBsAg decline (log10 IU/ml) was similar between Group A (0.399) and B (0.400), less in Group C (0.207), and none in Group D, and there was HBV DNA decline in the inactive chronic HBV groups. LDV and SOF are safe and well tolerated when given to chronic hepatitis B subjects and have modest antiviral activity, particularly when given in combination.

Immune-Mediated Pathogenesis in Dengue Virus Infection.

Dengue virus (DENV) infection is one of the major public health concerns around the globe, especially in the tropical regions of the world that contribute to 75% percent of dengue cases. While the majority of DENV infections are mild or asymptomatic, approximately 5% of the cases develop a severe form of the disease that is mainly attributed to sequential infection with different DENV serotypes. The severity of dengue depends on many immunopathogenic mechanisms involving both viral and host factors. Emerging evidence implicates an impaired immune response as contributing to disease progression and severity by restricting viral clearance and inducing severe inflammation, subsequently leading to dengue hemorrhagic fever and dengue shock syndrome. Moreover, the ability of DENV to infect a wide variety of immune cells, including monocytes, macrophages, dendritic cells, mast cells, and T and B cells, further dysregulates the antiviral functions of these cells, resulting in viral dissemination. Although several risk factors associated with disease progression have been proposed, gaps persist in the understanding of the disease pathogenesis and further investigations are warranted. In this review, we discuss known mechanisms of DENV-mediated immunopathogenesis and its association with disease progression and severity.

Efficacy and safety of CD24Fc in hospitalised patients with COVID-19: a randomised, double-blind, placebo-controlled, phase 3 study.

BACKGROUND: Non-antiviral therapeutic options are required for the treatment of hospitalised patients with COVID-19. CD24Fc is an immunomodulator with potential to reduce the exaggerated inflammatory response to tissue injuries. We aimed to evaluate the safety and efficacy of CD24Fc in hospitalised adults with COVID-19 receiving oxygen support. METHODS: We conducted a randomised, double-blind, placebo-controlled, phase 3 study at nine medical centres in the USA. Hospitalised patients (age ≥18 years) with confirmed SARS-CoV-2 infection who were receiving oxygen support and standard of care were randomly assigned (1:1) by site-stratified block randomisation to receive a single intravenous infusion of CD24Fc 480 mg or placebo. The study funder, investigators, and patients were masked to treatment group assignment. The primary endpoint was time to clinical improvement over 28 days, defined as time that elapsed between a baseline National Institute of Allergy and Infectious Diseases ordinal scale score of 2-4 and reaching a score of 5 or higher or hospital discharge. The prespecified primary interim analysis was done when 146 participants reached the time to clinical improvement endpoint. Efficacy was assessed in the intention-to-treat population. Safety was assessed in the as-treated population. This study is registered with ClinicalTrials.gov, NCT04317040. FINDINGS: Between April 24 and Sept 22, 2020, 243 hospitalised patients were assessed for eligibility and 234 were enrolled and randomly assigned to receive CD24Fc (n=116) or placebo (n=118). The prespecified interim analysis was done when 146 participants reached the time to clinical improvement endpoint among 197 randomised participants. In the interim analysis, the 28-day clinical improvement rate was 82% (81 of 99) for CD24Fc versus 66% (65 of 98) for placebo; median time to clinical improvement was 6·0 days (95% CI 5·0-8·0) in the CD24Fc group versus 10·0 days (7·0-15·0) in the placebo group (hazard ratio [HR] 1·61, 95% CI 1·16-2·23; log-rank p=0·0028, which crossed the prespecified efficacy boundary [α=0·0147]). 37 participants were randomly assigned after the interim analysis data cutoff date; among the 234 randomised participants, median time to clinical improvement was 6·0 days (95% CI 5·0-9·0) in the CD24Fc group versus 10·5 days (7·0-15·0) in the placebo group (HR 1·40, 95% CI 1·02-1·92; log-rank p=0·037). The proportion of participants with disease progression within 28 days was 19% (22 of 116) in the CD24Fc group versus 31% (36 of 118) in the placebo group (HR 0·56, 95% CI 0·33-0·95; unadjusted p=0·031). The incidences of adverse events and serious adverse events were similar in both groups. No treatment-related adverse events were observed. INTERPRETATION: CD24Fc is generally well tolerated and accelerates clinical improvement of hospitalised patients with COVID-19 who are receiving oxygen support. These data suggest that targeting inflammation in response to tissue injuries might provide a therapeutic option for patients hospitalised with COVID-19. FUNDING: Merck & Co, National Cancer Institute, OncoImmune.

Coronavirus Disease 2019-Associated Mucormycosis: Risk Factors and Mechanisms of Disease.

The severe surge of coronavirus disease 2019 (COVID-19) cases on the Indian subcontinent in early 2021 was marked by an unusually high number of COVID-19-associated mucormycosis (CAM) cases reported during this same period. This is significantly higher than predicted based on available data about prevalence and risk factors for this condition. This may be due to an unusual alignment of multiple risk factors for this condition. There is high background prevalence of mucormycosis in India likely from a high prevalence of risk factors, including undiagnosed or poorly controlled diabetes. COVID-19-induced immune dysregulation and immune suppression from steroid therapy increase the risk. The role of environmental exposure is unclear. System factors such as lack of access to healthcare during a pandemic may result in delayed diagnosis or suboptimal management with potentially poor outcomes. Here, we review currently identified risk factors and pathogenesis of CAM in a pandemic surge.

Humanized Mice for the Study of Dengue Disease Pathogenesis: Biological Assays.

Dengue is one of the most prevalent infectious diseases around the world, present in all continents and mainly affecting developing countries. With few tools to fight and study this disease, it is imperative to have reliable animal models that not only recapitulate human disease but also contain human components to understand the pathogenic mechanism and immune responses, allowing the development of new treatments and vaccines against dengue. Humanized mice are a significant advance in the development of in vivo models to understanding the relation of the human immune system and target organs such as the liver during the infection by dengue virus, allowing basic and preclinical research. In this chapter, we describe the use of humanized NSG mice (huNSG) for the study of dengue disease. The first model describes reconstitution of the human immune system by transplanting human CD34+ stem cells in newborn or adult NSG mice. The second model combines the reconstitution with CD34+ stem cells with the transplant of human primary hepatocytes. This dual reconstituted animal will have two of the major players involved in the development of dengue infection. However, there are still more biological components missing in this model for dengue, but researchers continue working to improve the huNSG model to reconstitute other human components.

Current Trends and Limitations in Dengue Antiviral Research.

Dengue is the most prevalent arthropod-borne viral disease worldwide and affects approximately 2.5 billion people living in over 100 countries. Increasing geographic expansion of Aedes aegypti mosquitoes (which transmit the virus) has made dengue a global health concern. There are currently no approved antivirals available to treat dengue, and the only approved vaccine used in some countries is limited to seropositive patients. Treatment of dengue, therefore, remains largely supportive to date; hence, research efforts are being intensified for the development of antivirals. The nonstructural proteins, 3 and 5 (NS3 and NS5), have been the major targets for dengue antiviral development due to their indispensable enzymatic and biological functions in the viral replication process. NS5 is the largest and most conserved nonstructural protein encoded by flaviviruses. Its multifunctionality makes it an attractive target for antiviral development, but research efforts have, this far, not resulted in the successful development of an antiviral targeting NS5. Increase in structural insights into the dengue NS5 protein will accelerate drug discovery efforts focused on NS5 as an antiviral target. In this review, we will give an overview of the current state of therapeutic development, with a focus on NS5 as a therapeutic target against dengue.

Immunopathology of Chronic Hepatitis B Infection: Role of Innate and Adaptive Immune Response in Disease Progression.

More than 250 million people are living with chronic hepatitis B despite the availability of highly effective vaccines and oral antivirals. Although innate and adaptive immune cells play crucial roles in controlling hepatitis B virus (HBV) infection, they are also accountable for inflammation and subsequently cause liver pathologies. During the initial phase of HBV infection, innate immunity is triggered leading to antiviral cytokines production, followed by activation and intrahepatic recruitment of the adaptive immune system resulting in successful virus elimination. In chronic HBV infection, significant alterations in both innate and adaptive immunity including expansion of regulatory cells, overexpression of co-inhibitory receptors, presence of abundant inflammatory mediators, and modifications in immune cell derived exosome release and function occurs, which overpower antiviral response leading to persistent viral infection and subsequent immune pathologies associated with disease progression towards fibrosis, cirrhosis, and hepatocellular carcinoma. In this review, we discuss the current knowledge of innate and adaptive immune cells transformations that are associated with immunopathogenesis and disease outcome in CHB patients.

Safety and immunogenicity of an HIV-1 gp120-CD4 chimeric subunit vaccine in a phase 1a randomized controlled trial.

A major challenge for HIV vaccine development is to raise anti-envelope antibodies capable of recognizing and neutralizing diverse strains of HIV-1. Accordingly, a full length single chain (FLSC) of gp120-CD4 chimeric vaccine construct was designed to present a highly conserved CD4-induced (CD4i) HIV-1 envelope structure that elicits cross-reactive anti-envelope humoral responses and protective immunity in animal models of HIV infection. IHV01 is the FLSC formulated in aluminum phosphate adjuvant. We enrolled 65 healthy adult volunteers in this first-in-human phase 1a randomized, double-blind, placebo-controlled study with three dose-escalating cohorts (75 µg, 150 µg, and 300 µg doses). Intramuscular injections were given on weeks 0, 4, 8, and 24. Participants were followed for an additional 24 weeks after the last immunization. The overall incidence of adverse events (AEs) was not significantly different between vaccinees and controls. The majority (89%) of vaccine-related AE were mild. The most common vaccine-related adverse event was injection site pain. There were no vaccine-related serious AE, discontinuation due to AE, intercurrent HIV infection, or significant decreases in CD4 count. By the final vaccination, all vaccine recipients developed antibodies against IHV01 and demonstrated anti-CD4i epitope antibodies. The elicited antibodies reacted with CD4 non-liganded Env antigens from diverse HIV-1 strains. Antibody-dependent cell-mediated cytotoxicity against heterologous infected cells or gp120 bound to CD4+ cells was evident in all cohorts as were anti-gp120 T-cell responses. IHV01 vaccine was safe, well tolerated, and immunogenic at all doses tested. The vaccine raised broadly reactive humoral responses against conserved CD4i epitopes on gp120 that mediates antiviral functions.

Campylobacter fetus aortitis in a patient with HIV.

A 36-year-old man with well controlled HIV developed Campylobacter fetus aortitis. To prevent aortic rupture, emergent surgical resection and neo-aortoiliac replacement with his left femoral vein was conducted. After surgical intervention, he was successfully treated with intravenous ertapenem for 6 weeks followed by oral amoxicillin for 3 months.

Evolution of Nipah Virus Infection: Past, Present, and Future Considerations.

Nipah virus (NiV) is a zoonotic paramyxovirus of the Henipavirus genus first identified in Malaysia in 1998. Henipaviruses have bat reservoir hosts and have been isolated from fruit bats found across Oceania, Asia, and Africa. Bat-to-human transmission is thought to be the primary mode of human NiV infection, although multiple intermediate hosts are described. Human infections with NiV were originally described as a syndrome of fever and rapid neurological decline following contact with swine. More recent outbreaks describe a syndrome with prominent respiratory symptoms and human-to-human transmission. Nearly annual outbreaks have been described since 1998 with case fatality rates reaching greater than 90%. The ubiquitous nature of the reservoir host, increasing deforestation, multiple mode of transmission, high case fatality rate, and lack of effective therapy or vaccines make NiV's pandemic potential increasingly significant. Here we review the epidemiology and microbiology of NiV as well as the therapeutic agents and vaccines in development.

Short-duration treatment with the novel non-nucleoside inhibitor CDI-31244 plus sofosbuvir/velpatasvir for chronic hepatitis C: An open-label study.

Combination regimens of direct-acting antiviral agents (DAAs) for chronic genotype 1 hepatitis C virus (HCV) infection given for 8 or 12 weeks have high cure rates. Shortened treatment durations that maintain high cure rates may lessen treatment barriers related to affordability and drug adherence. We enrolled 12 treatment-naïve adults with chronic genotype 1 HCV infection without cirrhosis in a single-center, open-label trial to receive 2 weeks of the highly potent and selective non-nucleoside inhibitor (NNI) CDI-31244 concurrent with 6 weeks of sofosbuvir/velpatasvir. The main efficacy endpoints were sustained virologic response at 12 (SVR12) and 24 (SVR24) weeks after treatment completion. In all patients, plasma HCV RNA levels rapidly decreased during the first 2 days of treatment and were below the lower limit of quantification by the end of the 6-week treatment period. Eight of 12 (67%) patients achieved both SVR12 and SVR24. Four patients had virological relapse at Week 10, 4 weeks after end of treatment. The most common adverse event was headache, occurring in five (42%) patients. Pharmacokinetic analysis showed no relevant drug interactions between CDI-31244, sofosbuvir, and velpatasvir. In this pilot study of short-duration combination therapy involving a novel NNI with a fixed-combination DAA, 8 of 12 treatment-naïve patients with chronic genotype 1 HCV infection without cirrhosis achieved virologic cure. Future trials might evaluate whether extending the NNI duration beyond 2 weeks with combination DAAs results in higher cure rates comparable with currently approved longer duration therapy.

Dengue Infections in Colombia: Epidemiological Trends of a Hyperendemic Country.

Dengue is a major public health problem in hyperendemic countries like Colombia, the understanding of the epidemiological trends is important for the development of efficient public health policies. We conducted a systematic review of the epidemiologic data on dengue in Colombia from 1971 to 2020. A total of 375 relevant citations were identified, 36 of which fulfilled the inclusion criteria. The data of dengue and severe dengue cases, infection fatality rate, and serotype distribution were used to understand and identify gaps in the epidemiological knowledge in Colombia. The epidemiology of dengue in this country was characterized by five main outbreaks in 1998, 2002, 2010, 2013, and 2019 with high fatality rates in comparison with the average values reported in the Americas. The case fatality rate of severe dengue exceeded 2% and all four serotypes co-circulate throughout the country with some regional variations. Overall, the behavior of dengue in Colombia is influenced by multiple factors including seasonal temperature variation and socioeconomic conditions. Additionally, the most important barriers in the epidemiological surveillance of dengue may be due to the insufficient notification rate in some regions and the low active search for the circulation of different serotypes.

Safety and Efficacy of Imatinib for Hospitalized Adults with COVID-19: A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: Primary Objective: To evaluate the efficacy and safety of oral administration of imatinib combined with the Best Conventional Care (BCC) versus placebo plus BCC in hospitalized patients with COVID-19. HYPOTHESIS: Addition of imatinib to the BCC will provide a superior clinical outcome for patients with COVID-19 compared with BCC plus placebo. This hypothesis is on the basis of 1) intralysosomal entrapment of imatinib will increase endosomal pH and effectively decrease SARS-CoV-2/cell fusion, 2) kinase inhibitory activity of imatinib will interfere with budding/release or replication of SARS-CoV-2, and 3) because of the critical role of mechanical ventilation in the care of patients with ARDS, imatinib will have a significant clinical impact for patients with critical COVID-19 infection in Intensive Care Unit (ICU). TRIAL DESIGN: This is an individual patient-level randomized, double-blind, placebo-controlled, two-parallel arm phase 3 study to evaluate the safety and efficacy of imatinib for the treatment of hospitalized adults with COVID-19. Participants will be followed for up to 60 days from the start of study drug administration. This trial will be conducted in accordance with the principles of the Declaration of Helsinki and the Good Clinical Practice guidelines of the International Conference on Harmonization. PARTICIPANTS: Inclusion Criteria: Patients may be included in the study only if they meet all of the following criteria: 1) Ability to understand and willingness to sign a written informed consent document. Informed consent must be obtained prior to participation in the study. For patients who are too unwell to provide consent such as patients on invasive ventilator or extracorporeal membrane oxygenation (ECMO), their Legally Authorized Representative (LAR) can sign the informed consent, 2) Hospitalized patients ≥18 years of age, 3) Positive reverse transcriptase-polymerase chain reaction (RT-PCR) assay for SARS-CoV-2 in the respiratory tract sample (oropharyngeal, nasopharyngeal or bronchoalveolar lavage (BAL)) by Center for Disease Control or local laboratory within 7 days of randomization, 4) Women of childbearing potential must agree to use at least one primary form of contraception for the duration of the study. EXCLUSION CRITERIA: Patients meeting any of the following criteria are not eligible for the study: 1) Patients receiving any other investigational agents in a clinical trial. Off-label use of agents such as hydroxychloroquine is not an exclusion criterion, 2) Pregnant or breastfeeding women, 3) Patients with significant liver or renal dysfunction at the time of screening as defined as: 3.1) Direct bilirubin >2.5 mg/dL, 3.2) AST, ALT, or alkaline phosphatase >5x upper limit of normal, 3.3) eGFR ≤30 mL/min or requiring renal replacement therapy, 4) Patients with significant hematologic disorder at screen as defined as: 4.1) Absolute neutrophil count (ANC) <500/µL, 4.2) Platelet <20,000/µL, 4.3) Hemoglobin <7 g/dL, 5) Uncontrolled underlying illness including, but not limited to, symptomatic congestive heart failure, unstable angina pectoris, uncontrolled active seizure disorder, or psychiatric illness/social situations that per site Principal Investigator's judgment would limit compliance with study requirements, 6) Known allergy to imatinib or its component products, 7) Any other clinical conditions that in the opinion of the investigator would make the subject unsuitable for the study. Both men and women of all races and ethnic groups are eligible for this trial. University of Maryland Medical Center, Baltimore, MD is the initiating site. The study may be opened in other centers on the basis of the accrual rate or the magnitude of the COVID-19 pandemic. INTERVENTION AND COMPARATOR: Imatinib: All doses of imatinib should be administered with a meal and a large glass of water. Imatinib can be dissolved in water or apple juice for patients having difficulty swallowing. In this study, patients with confirmed positive COVID-19 tests receive imatinib for a total of 14 days; 400 mg orally daily Days 1-14. Imatinib 400 mg tablets will be encapsulated using size 000 capsules and cellulose microcrystalline filler. For patients on ventilator or ECMO, imatinib will be given as oral suspension (40 mg/mL). To make the oral suspension, imatinib tablets will be crushed and mixed in Ora-sweet solution to yield a concentration of 40 mg/mL suspension by pharmacy. Additionally, in the absence of supportive microbiological testing results, we confirm that the in-use stability period for the prepared imatinib suspensions will be 24 hours at room temperature or 7 days at refrigerated conditions. The pharmacy staff will follow the American Society Health-System Pharmacists (ASHP) guidelines for handling hazardous drugs. Placebo: The matching placebo will be packaged by Investigational Drug Service Pharmacy at University of Maryland Medical Center. The placebos will be prepared using size 000 capsules and cellulose microcrystalline filler. Imatinib 400 mg capsules and placebo capsules will be identical form and color. For patients on ventilator or ECMO, placebo will be given as oral suspension with similar process for making imatinib suspension. Concomitant Medications/supportive care: In both arms, patients can receive concomitant available local standard of care antipyretics, antibacterials, antivirals, antifungals and anti-inflammatory including hydroxychloroquine at the discretion of the treating physician as necessary. For other drug-drug interactions particularly with CYP P450, the treating physician should consider the risk and benefit of drug administration based on available information. Co-administration of off-label immunomodulatory treatments for COVID-19 including but not limited to corticosteroids, sarilumab, clazakizumab, tocilizumab, and anakinra will be allowed but may affect interpretability of study outcomes. The timing, dosing, and duration of these treatments will be meticulously collected, including any of these treatments that may be used for participants who experience progression of COVID-19 disease after study enrollment. Two analyses will be performed, the primary analysis will compare the primary endpoint in the two trial arms irrespective of any other treatment; the second analysis will be stratified for co-administration of immunomodulatory drugs. MAIN OUTCOMES: The primary endpoint is the proportion of patients with a two-point improvement at Day 14 from baseline using the 8-category ordinal scale. The ordinal scale is an evaluation of the clinical status at the first assessment of a given study day. The scale is as follows: 1) Not hospitalized, no limitations on activities; 2) Not hospitalized, limitation on activities and/or requiring home oxygen; 3) Hospitalized, not requiring supplemental oxygen - no longer requires ongoing medical care; 4) Hospitalized, not requiring supplemental oxygen - requiring ongoing medical care (COVID-19 related or otherwise); 5) Hospitalized, requiring supplemental oxygen; 6) Hospitalized, on non-invasive ventilation or high flow oxygen devices; 7) Hospitalized, on invasive mechanical ventilation or ECMO; 8) Death. The secondary endpoints include: All-cause mortality at Day 28, All-cause mortality at Day 60, Time to a 2-point clinical improvement difference over baseline, Duration of hospitalization, Duration of ECMO or invasive mechanical ventilation (for subjects who are on ECMO or mechanical ventilation at Day 1), Duration of ICU stay (for subjects who are in ICU at Day 1), Time to SARS-CoV-2 negative by RT-PCR, Proportion of patients with negative oropharyngeal or nasopharyngeal swab for SARS-CoV-2 by RT-PCR on days 5, 10, 14, 21, and 28 after starting treatment, Proportion of subjects with serious adverse events, Proportion of subjects who discontinue study drug due to adverse events. The exploratory endpoints include: Determine the impact of treatment arms on IL-6 levels, Obtain blood/peripheral blood mononuclear cells (PBMCs) for storage to look at transcriptomics in severe disease, Association of major histocompatibility complex (MHC) with severity of illness, Mean change in the ordinal scale from baseline, Time to an improvement of one category from admission using an ordinal scale, Duration of hospitalization, Duration of new oxygen use, Number of oxygenation free days, Duration of new mechanical ventilation, Number of ventilator free days. RANDOMIZATION: Eligible patients will be uniformly randomized in 1:1 ratio to receive either imatinib or placebo for 14 days. Both groups will receive the BCC. The randomized treatment allocations use stratified, permuted block randomization with a variable block size; blocks are generated using a validated random number generator. In order to balance the severity of the respiratory illness between the two arms, randomization will be stratified based on radiographic findings and oxygen requirements: 1) Severe disease: evidence of pneumonia on chest X-ray or CT scan OR chest auscultation (rales, crackles), and SpO2 ≤92% on ambient air or PaO2/FiO2 <300 mmHg, and requires supplemental oxygen administration by nasal cannula, simple face mask, or other similar oxygen delivery device; 2) Critical disease: requires supplemental oxygen delivered by non-rebreather mask or high flow cannula OR use of invasive or non-invasive ventilation OR requiring treatment in an intensive care unit, use of vasopressors, extracorporeal life support, or renal replacement therapy. BLINDING (MASKING): The participants, caregivers, and the statistician are blinded to group assignment. The only people who are not blinded are Site Pharmacists. Blinding will be performed via a specific randomization process. Centralized, concealed randomization will be executed by the Primary Site's Pharmacist. Data on eligible consented cases will be submittedelectronically on the appropriate on-study form to the pharmacy, where the patient is randomized to imatinib or placebo. Imatinib 400 mg capsules and placebo capsules will be identical form and color. For patients on ventilator or ECMO, placebo will be given as oral suspension with similar process for making imatinib suspension. NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): The trial is designed as a double-blind, two-parallel arm, randomized controlled trial with a uniform (1:1) allocation ratio to: Arm A) Imatinib or Arm B) Placebo. Patients in both arms will receive the BCC per local institutional standards at the discretion of the treating physician. Group sample sizes of 102 in Arm A and 102 in Arm B achieve 80.6% power to detect a difference between the group proportions of 0.20. The proportion in Arm A (imatinib treatment arm) is assumed to be 0.30 under the null hypothesis and 0.50 under the alternative hypothesis. The proportion in Arm B (placebo control arm) is 0.30. The test statistic used is the two-sided Fisher's Exact Test. The significance level of the test is targeted at 0.05. The significance level actually achieved by this design is α=0.0385. The power of the test is calculated using binomial enumeration of all possible outcomes. The primary analysis will be conducted using an intention to treat principle (ITT) for participants who at least receive one dose of study drug or placebo. The sample size is not inflated for dropouts. All patients will be evaluable irrespective of the clinical course of their disease. TRIAL STATUS: Current protocol version is 1.2 from May 8, 2020. The recruitment started on June 15, 2020 and is ongoing. We originally anticipated that the trial would finish recruitment by mid 2021. We are aware of the enrollment requirement of approximately 200 patients, which is required to provide scientific integrity of the results. We are also aware of the fact that enrolling this number of patients in a single-site at University of Maryland Medical Center (UMMC) may take longer than expected, particularly taken into account other competing studies. For this reason, we are actively considering opening the protocol in other sites. After identification of other sites, we will fulfill all regulatory requirements before opening the protocol in other sites. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04394416 . First Posted: May 19, 2020; Last Update Posted: June 4, 2020. FDA has issued the "Study May Proceed" Letter for this clinical trial under the Investigational New Drug (IND) number 149239. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.