View clinical trials related to Yellow Fever.
Filter by:VYF03 is a phase II, randomized, parallel-group prevention study with 2 arms, active-controlled (Stamaril), observer-blind, multi-center study to assess the non-inferiority of the immune response, in terms of seroconversion rates of the investigational vaccine candidate vYF to the licensed Stamaril, in adults aged 18 years up to 60 years in Europe (EU). The safety and immunogenicity profile of vYF in a cohort of Asian population of Chinese origin outside of China will also be described. The study will also assess the immunogenicity profiles and the safety profiles of vYF and Stamaril. Participants will be randomized in a 2:1 ratio to receive a single subcutaneous injection of either the vYF vaccine (380 participants in EU and 80 participants of Chinese origin in Asia) or Stamaril (190 participants in EU and 40 participants of Chinese origin in Asia), on Day 01. The duration of each participant's participation will be approximately 5 years.
The primary objective of the study is to demonstrate the non-inferiority of the antibody response in terms of seroconversion rate 28 days after vaccine administration of one dose of yellow fever vaccine (vYF) compared to the antibody response after one dose of the YF-VAX control vaccine in yellow fever naïve participants. The secondary objectives of the study are: - To describe the immune response to yellow fever in both vaccine groups before and after vYF or YF-VAX administration. - To describe the safety profile of vYF vaccine in comparison to the safety profile of the control YF-VAX. - To describe the biosafety profile of vYF in comparison to the biosafety profile of the control YF-VAX.
Hypothesis: Infections other than HIV can cause LN inflammation and collagen damage to the fibroblastic reticular cell network (FRCn), which will lead to CD4 T cell depletion and impaired vaccine responses. This protocol will study yellow fever vaccine (YFV) in two cohorts of people, one from Uganda and the other from Minnesota where we collect lymphoid tissues (LT) and peripheral blood monocytes (PBMCs) before and after vaccination using a new technique to catalog infectious burden of the individual, determine the relationship between IA, Infections, and immune response.
Participating countries: Belgium Context: In June 2013, WHO notified that "a single dose of YF vaccine is sufficient to confer sustained life-long protective immunity against YF disease and that a booster dose is not necessary". . For HIV infected persons the recommendation was less stringent and the position paper concluded that hiv infected persons may "hypothetically, benefit from a second dose or booster dose ".1 Recently, WHO changed the recommendations about a booster dose of YF vaccine, based on the fact that serum neutralizing antibodies against YF are still at detectable levels after 20-35 years and probably lifelong in immunocompetent patients. Unfortunately, data on persistence of Neutralizing antibodies Titers (NT) in immunocompromised patients are missing and only few studies reported data about HIV-infected patients. Additional data are needed. Primary objective: To assess presence / persistence of Neutralizing Titers (NT) of antibodies after YF immunization in HIV-infected patients. Secondary objectives: 1. To identify risk factors for early and late waning of NT after YF immunization 2. To modelize kinetics of NT after YF immunization in different subpopulations of HIV patients, including population of young HIV patients infected vertically 3. To identify risk factors for absence of seroconversion in the year after YF immunization 4. To compare persistence of NT in HIV patients infected vertically or not vertically 5. To quantify seroconversion rate after YF vaccination Methodology / study design This study is a single arm, non randomized, cross-sectional, multicenter study in AIDS Reference Centers from Belgium. The maximum duration of the study for each patient will be 1 visit, consisting of: - the screening and inclusion visit (single visit V1) to check the patient eligibility, sign informed consent, perform the biologic tests necessary for the study and answer the questionnaire - whenever possible, an additional serum / plasma sample coming from serabank / plasmabank will be identified for each patient. This sample must have been taken during the year following YF immunization. - data about patient's HIV history has to be extracted from the HIV database or from patients' file Estimated enrolment 750 patients + 30 patients infected vertically with HIV Primary outcome Number of HIV patients with protective YF NT ≥ 1:10 at different timepoints after YF immunization Secondary outcomes 1. Number of patients with protective YF NT ≥ 1:10 in the year following YF immunization 2. Risk factors (demographics and immunovirological parameters, antiretroviral treatment) for absence of seroconversion in the year following YF immunization 3. Risk factors (demographics and immunovirological parameters, antiretroviral treatment) of early waning (before 10 years) of YF NT 4. Risk factors (demographics and immunovirological parameters, antiretroviral treatment) of late waning (after 10 years) of YF NT Eligibility Inclusion criteria 1. Infection with HIV-1 (vertical transmission or not) 2. Immunization with at least one injection of YF vaccine (Stamaril®,17D strain Rockefeller, Sanofi Pasteur) with proof of vaccine administration 3. Informed consent signed prior to any study procedure Exclusion criteria Inability to give informed consent Substudies - Whenever possible, an additional sera or plasma sample from the year following YF vaccine will be selected and analyzed to assess early seroconversion rate - Whenever possible, an additional sera or plasma sample from the year before YF vaccine will be selected and analyzed to assess seroconversion rate - In CHU Saint-Pierre, an additional cohort of patients infected vertically with HIV will be selected and will participate to the study
In a previous study by the researchers' group, the researchers' investigate the duration of yellow fever post-vaccination immunity in vaccinated children between 9 and 23 months of age. However, in this study, samples of children in the pre-vaccine period, also known as unvaccinated children samples (NV) have not been investigated. It is believed that to seek evidence about the immune status in the medium and long term after vaccination against yellow fever is necessary to investigate paired samples of children not vaccinated (NV), with re-evaluation 30-45 days after primary vaccination. The proposed study is to consolidate aspects of humoral (neutralizing antibodies) and cellular (phenotypic and functional parameters of T cells and memory B) by means of complementary longitudinal investigation children, 9-23 months old, unvaccinated (NV) and 30-45 days after primary vaccination.
The study main objective is to assess the immune status of children and adults who have never vaccinated, they will receive the first dose of 17DD yellow fever vaccine provided by the study and will be monitored for 10 years. Depending on the results of the analyzed of the data, the period of monitoring may be extended.