19 Clinical Trials for Various Conditions
The goal of this clinical trial is to assess the immune response to the yellow fever vaccine 17D in adults with prior 17D vaccination. The main questions this study aims to answer are: * how does prior vaccination affect antibody responses to re-vaccination? * how does prior vaccination affect the immune cell response to re-vaccination? Participants will: * have been previously vaccinated with 17D. * be re-vaccinated with 17D. * provide medical and travel histories. * provide a blood sample prior to vaccination * provide a blood sample approximately every other day for 14 days after vaccination. * provide a blood sample approximately 28 days after vaccination. * complete a daily diary of symptoms following vaccination for 14 days. * report any additional symptoms after 14 days.
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.
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.
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.
A randomized clinical trial comparing fractional dose Yellow Fever vaccination to the full dose among children aged 9-23 months in Uganda. Children will have immune response assessed at baseline, 4 weeks, and 12 months after vaccination. Enrolled participants will be randomized to one of three arms: A. One-fifth fractional dose (0.1 ml) administered subcutaneously B. One-half fractional dose (0.25 ml) administered subcutaneously C. Full dose (0.5 ml) administered subcutaneously
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.
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.
This study is a multi-center, double-blind, placebo-controlled, Phase I study to evaluate the safety, reactogenicity, tolerability, and immunogenicity of Modified Vaccinia Ankara-Bavarian Nordic-Yellow Fever (MVA-BN-YF) in Flavivirus-naive healthy male and non-pregnant female adult subjects. There are six dose groups in this study. Subjects who have never received a licensed or investigational smallpox vaccine will be randomized to Groups 1-5 and vaccine administration and follow-up will be conducted in a double-blinded fashion. Subjects who have previously received two, 1 x 10\^8 TCID50 doses of Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) between 19 and 45 days apart by s ubcutaneous (SC) or intramuscular (IM) routes will be enrolled in Group 6 and will be dosed open-label. Since this is a first in human, phase I study, a sentinel cohort will be utilized. The first two subjects (1st sentinel group) one at each clinical site will be randomized to Group 2 or 3 and vaccinated with MVA-BN-YF with or without Montanide ISA 720 adjuvant (ISA 720). Subjects and study personnel will be blinded as to whether ISA 720 was administered. The primary objectives are the: 1) assessment of the safety, tolerability, and reactogenicity of MVA-BN-YF vaccine administered with or without ISA 720; 2) comparison of the safety, tolerability, and reactogenicity of MVA-BN-YF vaccine administered with or without ISA 720 with Yellow Fever Vaccine (YF-VAX) and MVA-BN.
The aim of this study was to evaluate the administration of CYD dengue vaccine serotypes (1, 2, 3 and 4) following a compressed schedule in 3 different populations. Primary Objectives: * To describe the humoral immune response to each of the 4 parental dengue virus serotypes at baseline and 28 days after CYD dengue vaccine Dose 3 in Group 1 (Month \[M\] 13) and Group 2 (M07), irrespective of whether or not Yellow Fever (YF) vaccine has been previously administered. * To describe the persistence of the humoral immune response to each of the 4 parental dengue virus serotypes 6 months after CYD dengue vaccine Dose 3 in Group 1 (M18) and Group 2 (M12), irrespective of whether or not YF vaccine has been previously administered. Secondary Objective: * To describe the humoral immune response to each of the 4 parental dengue virus serotypes at baseline and 28 days after CYD dengue vaccine Dose 1 and Dose 2 in Groups 1 and 2, irrespective of whether or not YF vaccine has been previously administered. * To describe the humoral immune response to each of the 4 parental dengue virus serotypes at baseline and 28 days after CYD dengue Dose 1 in the combined YF-participants in Group 1 (N=60) and Group 2 (N=60), and in Group 3 (N=120). * To describe by FV status at baseline the humoral immune response to each of the 4 parental dengue virus serotypes at baseline and 28 days after each injection of CYD dengue vaccine in Groups 1, 2, and 3. * To describe the safety profile after each injection of CYD dengue vaccine and/or YF vaccine.
The yellow fever vaccine is a live, attenuated virus that results in a robust immune response, especially in the T cell compartment. The researchers have been studying immune responses to live viral infections using the yellow fever vaccine as a model for a live viral infection. In this study, the researchers are interested in looking at the processing and lifespan of yellow fever specific CD8 T cell by measuring DNA replication and cell proliferation in humans using a naturally occurring stable isotope called deuterium.
The objective of this study is to study immune memory generated against the yellow fever (YFV) vaccine in participants who have previously received the vaccine. Volunteers will not receive vaccine shots; only immune responses to previous yellow fever vaccination will be studied. The study involves one or multiple blood draws.
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: 1. The seroconversion rates and GMT neutralizing antibody titers for all dose groups combined on Days 21 and 42. 2. The reverse cumulative distribution curve of antibody titers on Days 21 and 42 for each dose group and for all dose groups combined 3. 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.
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.
The goal of this study is to use the live attenuated Yellow Fever Vaccine as a safe and effective model for viral infection to understand human immune response to viral antigens. Study participants will receive the yellow fever vaccine and participation in the study may be as short as one month or as long as one year, depending on immune responses.
The investigators at Rockefeller University are doing this research to study how the immune system responds to viruses and other infectious agents by using the yellow fever 17D vaccine as a model. The YFV-17D vaccine is one of the safest and most effective vaccines known and has been used to vaccinate humans against yellow fever virus (YFV) infection since the 1930s. By studying how the human immune system responds to the YFV vaccine we hope to learn more about the normal functioning of the immune system so that it might be possible to design new, more effective types of vaccines to prevent important infectious diseases. The reason for doing this research is: Currently there is very little information about which factors determine the effectiveness of the initial (primary) immune response to a foreign substance (antigen), such as a virus, that person may be exposed to. There is also very little known about what determines how effectively and for how long a person's immune system can react to the same antigen to prevent another infection. Studies in animals have given us important information about how the immune systems of other animals behave upon initial or repeated exposure to antigens,but these topics have not been studied in detail in humans. The following hypotheses will be tested: * The magnitude of the initial expansion of T lymphocytes (the "clonal burst") specific for the infecting virus determines the level at which memory T cell responses are generated against the specific viral antigen and the duration of the memory T cell response generated in the body. * The majority of CD8 T cells generated after immunization are yellow fever specific and not "bystander activation" of non-specific cells.
The purpose of this study is to determine whether immune globulin can limit the amount of yellow fever vaccine virus present in the blood after vaccination without compromising the immunity associated with the yellow fever vaccine. The study will enroll 80 participants in two groups of 40 each. The first group will receive the yellow fever vaccine with salt-water placebo. The second group will receive yellow fever vaccine with immune globulin. The amount of vaccine virus and immune response in both groups will be compared. Yellow fever vaccine has been used to protect humans against Yellow Fever Vaccine disease since the 1930s.
The purpose of this study is to assess the safety of vYF (investigational vaccine) compared to the safety of YF-VAX (YF licensed vaccine) in adults aged 18 years up to 60 years. Study details include: * The study duration will be up to approximately 6 months. * One single dose of the study intervention (vYF or YF-VAX) will be administered subcutaneously at the 1st visit. * The visit(V) frequency will be Day(D) 01 (V01) and D29 (V02). Two telephone calls will be planned at D15 and Month(M)6. Number of Participants: A total of 640 participants are expected to be included in the study in a 3:1 ratio (vYF: YF-VAX): Group 1: vYF; N=480 Group 2: YF-VAX; N=160 Study Arms and Duration: Randomized, active control (YF-VAX). 6 months duration per participants. Eligible participants will be randomized in a 3:1 ratio to receive, subcutaneously, a single dose of vYF or YF-VAX vaccines on D01.