Active clinical trials for "Yellow Fever"

The purpose of this study is to assess the immunogenicity, safety, and reactogenicity of the SB257049 candidate malaria vaccine when co-administered with Vitamin A, measles, rubella and yellow fever vaccines to children aged 6 months at the first vaccination.

The purpose of this study is to obtain safety, tolerability, and immunogenicity data on the co-administration or sequential administration of Chimeravax™-JE vaccine and STAMARIL®. Objectives: Safety: Obtain safety and tolerability data of a single, fixed dose of ChimeriVax™-JE administered concurrently, one month before or one month after STAMARIL® to adult volunteers (≥ 18 to ≤ 55 years) without prior Japanese encephalitis (JE) or yellow fever (YF) vaccination. Immunogenicity: Obtain data on the antibody response to a single, fixed dose of ChimeriVax™-JE administered concurrently, one month before or one month after STAMARIL® to adult volunteers without prior JE (or YF) vaccination. Assess the durability of the immune response in adult volunteers 6 months after administration of ChimeriVax™-JE and STAMARIL®.

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.

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.

The main purpose of this study is to assess the immunogenicity and safety of the concomitant and sequential administration of yellow fever (YF) vaccine and tetravalent dengue vaccine (TDV) in healthy participants aged 18 to 60 years living in country non-endemic for both dengue and YF.

The Phase 1 trial is a single-center, randomized, double blind, placebo-controlled, dose-ranging out-patient study designed to provide the first clinical data on the safety, tolerability and immunogenicity of XRX-001 inactivated yellow fever vaccine in 60 healthy male and female volunteers, 18-49 years of age. Subjects will receive two inoculations of one of two dose levels of XRX-001 vaccine. A control group will receive placebo. Safety will be determined by the incidence and severity of adverse events in each treatment group and in the combined cohorts in the double blind treatment period up to 42 days post-vaccination. Subjects will also be followed-up at 3, 6 and 12 months to determine severe adverse events (SAEs) and changes in health status. Efficacy will be assessed by neutralizing antibody response to the vaccine. The co-primary immunogenicity endpoints will be the dose-response analysis of seroconversion rates (fourfold or greater increase in neutralizing antibody titer between baseline and Day 42) and of the 50% plaque reduction neutralization test (PRNT50) geometric mean titers (GMT) at Day 42. Secondary immunogenicity endpoints will include: The seroconversion rates and GMT neutralizing antibody titers for all dose groups combined on Days 21 and 42. The reverse cumulative distribution curve of antibody titers on Days 21 and 42 for each dose group and for all dose groups combined The duration of antibody titers displaying the seroconversion rate and GMT across all time-points to Month 12, by treatment group and for both dose groups combined.

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).

Epidemic viral diseases have become more prevalent in recent years. Among the various strategies to prevent such epidemics, vaccination is the most cost-effective. However, populations that are immunized are typically already exposed to multiple previous vaccinations or natural infections. Studies from this and other laboratories have revealed that pre-existing dengue antibodies can either inhibit or enhance subsequent dengue infection depending on the pre-existing antibody levels. While cross-reactive antibody is potentially pathogenic in dengue, how it impacts immune response to vaccination is unclear. Indeed, aggregated at the site of vaccination and the respective draining lymph nodes are antigen-presenting and immune regulatory cells that express Fc receptors and play pivotal roles in determining the magnitude and polarity of the immune response. Vaccine uptake by these antigen-presenting cells may thus be either inhibited or enhanced when vaccines are opsonized with cross-reactive antibodies. In view of the limited knowledge on how cross-reactive antibodies affect vaccination outcome, investigators propose here a study that exploits the known cross reactivity between Japanese encephalitis (JE) virus antibody and yellow fever (YF) vaccine. Investigators hypothesize that cross-reactive antibodies impacts antibody response to YF at the point vaccination in a concentration-dependent manner by altering both vaccine uptake and the innate immune response by antigen presenting cells. Investigators will structure an open label clinical trial on sequential vaccination with JE and YF vaccines, with different time intervals between vaccinations. This would test immune response to YF vaccination in subjects with different titer of cross-reactive JE vaccine-derived antibodies.

The main objective of the Atopic Dermatitis and Vaccinia Immunization Network (ADVN) is to reduce the risk of the fatal reaction, eczema vaccinatum (EV), to the smallpox vaccination in those with atopic dermatitis (AD). Since vaccination with live vaccinia virus (VV) in individuals with AD increases the risk of EV, a yellow fever vaccine was chosen. The purpose of this study is to determine the immune response to a yellow fever vaccine in adults with AD.

It is thought that vaccines trigger innate inflammatory responses to induce antigenspecific adaptive immunity (the desired effect), but excessive inflammation may lead to serious inflammatory complications or unwanted side effects. Currently there is a lack of reliable biomarkers (a measurable biological response that predicts something) able to predict severe inflammation and this has resulted in the development of several vaccines being terminated and the withdrawal of some licensed vaccines which were associated with inflammatory complications. This study is part of the BIOVACSAFE project which is a 5year €30M project funded by the Innovative Medicine Initiative. The project involves a series of clinical studies using licensed vaccines as benchmarks to generate clinical data on inflammation and identify biomarkers that can be used to predict acceptable reactogenicity. The target is to identify biomarkers that can predict the occurrence of beneficial and detrimental effects in response to a vaccine. Such biomarkers could be used in future vaccine development programs to optimize selection of vaccine candidates with a profile that will be unlikely to generate worrisome safety signals once they are in generalized use. This study is one in a series of "training" studies which will each use different licensed vaccines that are prototypical representatives of a class of vaccine used in a particular target population. Forty eight subjects will be randomised into three groups to receive: A) Varicella zoster vaccine (n = 20), B) Yellow Fever vaccine (n = 20), C) Saline placebo (n = 8). Following a screening visit, participants will undergo a seven day residential visit which will include immunization and intensive monitoring of physiological (e.g. heart rate, oral temperature, blood pressure) metabolic and immune (innate and adaptive) parameters. This visit will be followed up by four outpatient visits with further monitoring and blood samples.