View clinical trials related to Yellow Fever.
Filter by:This is an open-label, randomized, exploratory study to evaluate the human immune response to reduced subcutaneous (SQ) dosing of Yellow Fever vaccine compared to the standard FDA approved subcutaneous vaccination dose. The current dose of the US FDA licensed Yellow Fever vaccine is approximately 55,000 plaque-forming unit(s) (PFU) in 0.5 mL administered SQ. Using the licensed dosage as standard, investigators are evaluating reduced doses of 1/5th (0.10 mL) and 1/10th (0.05 mL) Yellow Fever vaccine (YF-VAX).
This trial will be a randomized, placebo controlled, double-blind (within dosing group), dose escalation Phase 1 trial, evaluating dosages of 1 mcg and 5 mcg of HydroVax-002 YFV vaccine given intramuscularly on Day 1 and Day 29 in up to 25 healthy adults healthy adults ≥ 18 and < 50 years of age. The primary objective is to assess the safety, reactogenicity, and tolerability of the HydroVax-002 YFV vaccine administered intramuscularly in a two-dose series on Days 1 and 29 at a dose of 1 mcg or a dose of 5 mcg.
To determine the efficacy of metformin in reducing the rate of symptomatic YF17D infection, and to elucidate the effects of metformin on YF17D viremia and the downstream adaptive immune response, we hereby propose a randomised, double-blind, placebo-controlled clinical trial that is coupled with a system biology approach. We plan to recruit 44 healthy volunteers aged 21-40 years, with a Body Mass Index of 20-25 kg/m2, have no known drug allergies and are not currently receiving regular immune-modulating therapy such as metformin, NSAIDs, paracetamol, corticosteroids or statins. The age range that we propose will ensure that our volunteers are likely to be healthy and not be on long-term medication for other concurrent medical conditions. This would abrogate the confounding effect of YF17D infection enhancement by cross reactive antibodies that we have previously shown. Informed written consent will be obtained before any physical examination is performed. All consented subjects will undergo screening which includes a full physical examination, vital signs measurement, clinical laboratory tests and urine pregnancy test (for female subjects of child-bearing potential) Eligible subjects will be randomized 1:1 to either metformin 1000mg or placebo twice daily for 7 consecutive days (Days 1-7). On Day 4, subjects will be administered one dose of YF17D before study drug dosing. Aim 1 tests the hypothesis that prophylactic metformin reduces ER stress and thus attenuates the post-infection pro-inflammatory response for reduced rate of symptomatic outcome. The primary objective for Aim 1 is to determine the efficacy of metformin in reducing the rate of symptomatic YF17D infection using a randomized placebo-controlled clinical trial. Aim 2 explores the effectiveness of metformin, either through its action on ER stress or other pathways that differentially regulate the expression of pro- and anti-viral host factors, in inhibiting live attenuated vaccine infection and downstream adaptive immune responses. The primary objective for Aim 2 is to elucidate the effects of metformin on YF17D viremia and the downstream adaptive immune response.
The primary objectives of the study are: - To describe the safety profile of each of the 3 dosages of vYF and of YF-VAX® within the 28 days post-vaccination and up to the 6 months (Day 180) post-vaccination visit - To describe the antibody responses elicited by each of the 3 dosages of vYF and by YF-VAX on Day 0 pre-vaccination and then on Day 10, Day 14, Day 28 and 6 months (Day 180) post-vaccination overall and by baseline flavivirus serostatus - To quantify the detectable yellow fever (YF) vaccinal viremia in each vaccine groups (vYF and YF-VAX) in a subset of subjects on Day 0 visit, Day 1 visit, Day 3 visit, Day 5 visit, Day 7 visit, Day 10 visit, and Day 14 visit.
In the recent past there has been a number of large urban Yellow Fever outbreaks in sub-Saharan Africa, tropical South Americas, The demand for Yellow Fever vaccines in response to the large urban outbreaks occurring concurrently and the risk of further spread through Africa and to Asia was larger than the available global supply. In this situation, the World Health Organisation (WHO) developed recommendations for the use of fractional doses of Yellow Fever vaccine as a dose-sparing strategy. These recommendations were based on data from a limited number of clinical trials, none of which had been conducted in Africa. This was due to the uncertainties on the minimum dose requirement. Our study complements a study which is comparing full standard dose to 1/5th of standard dose of all four WHO-prequalified YF vaccines in adults (ClinicalTrials.gov number: NCT02991495), and is currently ongoing at KEMRI CGMRC and Epicentre, Mbarara which is designed to answer questions on the use of current stock of YF vaccines with a potency as close as possible to each manufacturers' minimum release. Data from this trial will inform a WHO recommendation on using 1/5th of the current standard dose of vaccine for outbreak control. However, since many vials will contain excess YF vaccine such that 1/5th of a vial is likely to be substantially above the current minimum potency requirements, these data may not be scientifically explanatory regarding the minimum dose required for preventive use. The new complementary study, aims to determine the lowest YF vaccine dose that is non-inferior to the current standard full dose among populations in sub-Saharan Africa. The study will be conducted in Kenya (KEMRI Center for Geographical Medicine Research-Coast (CGMR-C), Kilifi) and Uganda (Epicentre, Mbarara) with trial participants recruited at both sites, using vaccine from one WHO-prequalified manufacturer (Institut Pasteur de Dakar, Senegal (IPD)).
Previous studies have shown that a small incentive can have a large impact on health behaviors like vaccinating children. New Incentives, an international non-governmental organization (NGO), aims to boost demand for immunization by offering cash incentives to caregivers who have their child vaccinated at a program clinic. In collaboration with New Incentives, IDinsight is conducting a study to see whether this approach will increase immunization in North West Nigeria. This study aims to investigate whether giving cash to caregivers in North West Nigeria who bring their infants to receive vaccination against common infections (tuberculosis, diphtheria, tetanus, pertussis, hepatitis B virus (HBV) infection, Haemophilus influenzae Type B (Hib), pneumococcal bacteria, measles, rotavirus, polio, yellow fever) increases the proportion of children who are immunized. The study's main hypothesis is that New Incentives' program will increase the percentage of children immunized with BCG, any PENTA, or Measles 1 by an average increase of at least 7-percentage points across all program clinics that share a similar profile to the clinics New Incentives will operate in at scale. The study is taking place in Jigawa, Katsina, and Zamfara States between August 2017 and January 2020.
Yellow Fever is an acute viral hemorrhagic disease caused by the Yellow Fever Virus (YFV), a re-emerging arbovirus transmitted by the same mosquito vector (Aedes aegypti) that transmits Dengue virus (DENV) and Zika virus (ZIKV). YFV is endemic in tropical and subtropical areas of South America and Africa, causing an estimated 200,000 infections and 30,000 deaths annually. It has now become a growing public health problem, rapidly spreading throughout the two (2) continents in a cyclical pattern. With climate change, global travel and urbanisation, which increase the chance for mosquito-borne diseases to spread rapidly, the risk of YFV establishing its foothold in the Asia-Pacific region with periodic epidemic bursts remains a real public health concern. Although there is currently a safe and effective vaccine available on the market, global shortages of supplies have severely hampered any efforts in the prevention and control of YFV outbreaks. To date, no YFV therapy (biologic or small molecule) has advanced to clinical trials. TY014 will be the first therapeutic in the world, specifically targeting YFV, to enter clinical trials. It is anticipated that a monoclonal antibody therapeutic could be administered to infected cases to reduce disease severity within the patient and their contacts. This is a Phase 1, first-in-human TY014, YFV monoclonal antibody (mAb), study to be conducted in two (2) arms: - Safety Arm (1A): Healthy adult volunteers - Efficacy Arm (1B): Healthy adult volunteers challenged with YF-17D Vaccine Strain 24 hours prior to TY014 dosing TY014 will be administered once through single IV infusion over 30 minutes. Total duration of study participation is estimated at approximately 114 days from the date of screening. The main objectives of this study are to: (a) evaluate the safety of TY014 in healthy adult volunteers, and (b) evaluate the safety of TY014 in YF-17D Vaccine Strain-challenged healthy adult volunteers. Percentage aviremia of YF-17D Vaccine Strain-challenged subjects within 48 hours after IV infusion of TY014 will also be assessed.
This is a passive enhance safety surveillance (ESS) of Stamaril® vaccine in Korea. The objective is to collect suspected related adverse events following vaccination with Stamaril® in routine practice.
The immune system is composed of diverse cell types with different functions that act together in order to defend against infection. This pilot study will test a new technology for studying these many different cell types at very large numbers at the level of individual cells. This method will then be used to identify the cell types and functions important for the immune response to the highly protective yellow fever vaccine, which will improve our understanding of effective vaccine features.
According to World Health Organization (WHO), since December 2016, Brazil is showing a significant increase in cases of yellow fever in humans. In view of this, vaccination is suitable for residents and travelers to the risk area. However, for immunosuppressed patients there is a formal recommendation not to vaccinate with live virus vaccine. On the other hand, the safety and efficacy of the vaccine has been demonstrated in patients with HIV, and safety and seroconversion have also been demonstrated in patients with rheumatic disease who were inadvertently revaccinated for yellow fever. Faced with the impossibility of leaving the high-risk area for some patients the vaccination could be released to only those who have low level of immunosuppression as suggested by some recommendations of medical societies. The availability of a fractional vaccine in the State of São Paulo, which has proved its efficacy, opens the possibility of exposure to a lower number of copies of the virus in the first exposure of immunosuppressed patients, allowing, if necessary, a safer revaccination, after 28 days to obtain of a more effective immunogenic response. The objectives of the study are to evaluate the immune response of the immunization with fractional yellow fever vaccine (neutralizing antibodies) in patients with systemic autoimmune rheumatic diseases residing in a high-risk area. Secondarily, evaluate the possible association between immunogenicity and vaccination with: demographic data, clinical and laboratory activity of the disease in patients with chronic rheumatic diseases, evaluate the curve of viremia and report adverse events. Patients and healthy controls will be vaccinated for yellow fever in the Immunization Center of Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP). The patients' screening for exclusion and inclusion criteria will be done at the rheumatology outpatient clinic after medical evaluation. For the controls will be the routine screening of the Immunization Center. The vaccination protocol will be a fractional dose of the yellow fever vaccine on day D0 for both groups. Patients will be evaluated on day D0, D5, D10, D30-4 and D365 and controls only on days D0, D10, D30-45 and D365 for aspartate aminotransferase (AST), alanine aminotransferase (ALT), platelets, urea and creatinine, immunoglobulin M (IgM) by immunofluorescence for Yellow Fever, viremia, autoantibodies.