Active clinical trials for "Vector Borne Diseases"

This is an open-label, adaptive study using the P. falciparum induced blood stage malaria (IBSM) model to characterise the pharmacokinetic/pharmacodynamic (PK/PD) profile and safety of MMV367 (the IMP). Up to 18 participants will be enrolled in cohorts of up to 6 participants each. The study will proceed as follows for all participants: Screening period of up to 28 days to recruit healthy adult participants. Day 0: Intravenous inoculation with approximately 2,800 viable P. falciparum-infected red blood cells. Days 1-3: Daily follow up via phone call or text message. Days 4-7: Daily site visits for clinical evaluation and blood sampling to monitor malaria parasite numbers via quantitative polymerase chain reaction (qPCR). Day 7 PM: Start of confinement within the clinical trial unit. Day 8: Administration of a single oral dose of the IMP (MMV367). Different doses of MMV367 will be administered across and within cohorts in order to effectively characterise the PK/PD relationship. Days 8-11: Regular clinical evaluation and blood sampling while confined to monitor malaria parasite numbers and measure MMV367 plasma concentration. Day 11 AM: End of confinement within clinical trial unit. Days 12-23: Outpatient follow-up for clinical evaluation and blood sampling. Day 24: Initiation of compulsory definitive antimalarial treatment with Riamet® (artemether/lumefantrine) and/or other registered antimalarials if required. Treatment will be initiated earlier than Day 24 in the event of: Insufficient parasite clearance following IMP dosing Parasite regrowth following IMP dosing Characterising the pharmacokinetic/pharmacodynamic relationship of MMV367 Participant discontinuation/withdrawal, Investigator's discretion in the interest of participant safety. Day 27: End of study visit for final clinical evaluation and to ensure complete clearance of malaria parasites.

Malaria is a major public health problem. There were around 240 million cases of malaria and 627,000 deaths worldwide in 2020. There is a great need for a safe, effective malaria vaccine and the team at University of Oxford is trying to make vaccine(s) which can prevent serious illness and death. This study is being done to assess an experimental malaria vaccine for its ability to prevent malaria illness. This is done using a 'blood-stage challenge model'. This is when volunteers are infected with malaria parasites using malaria-infected red blood cells. The vaccine we are testing in this part of the study is called "RH5.2-VLP". It is given with an adjuvant called "Matrix-M". This is a substance to improve the body's response to a vaccination. RH5.2-VLP is being tested for the first time in humans in this trial. The Matrix-M adjuvant has been given to tens of thousands of people, with no major concerns, such as illness. The aim is to use this vaccine and adjuvant to help the body make an immune response against parts of the malaria parasite. This study will assess: The safety of the vaccine in healthy participants. The response of the human immune system to the vaccine. The ability of the vaccine to prevent malaria illness (Group 2 only). We will do this by giving healthy adult participants (aged 18-45) three of the vaccines and/or expose participants to malaria infection at the Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital in Oxford. We will then do blood tests and collect information about any symptoms that occur after vaccination. There will be 19 to 54 visits, lasting between 3 months to 2 years and 2 months.

The primary objective of the study is to demonstrate and quantify the protective efficacy of a single Spatial Repellent (SR) product, in reducing malaria infection in a human cohort. The study design will be a prospective cluster Randomized Control Trial (cRCT).

The Pacific region is facing several emerging and neglected diseases notably mosquito-borne diseases as malaria or arboviroses among which dengue, Ross River, chikungunya and Zika. These diseases are an important cause of illness and death in the Pacific and the occurrence of arboviruses has increased in the recent years. In humans, these mosquito-borne diseases often have very similar clinical presentations (an acute febrile syndrome often self-limiting). However, these infections can progress to severe and fatal prognosis. Numerous arboviroses outbreaks and in particular dengue outbreaks have affected Vanuatu for decades. Except for DENV and Zika for which epidemiological and virological data are available for Vanuatu, the knowledge on chikungunya and Ross River circulation is very limited and needs to be defined as both viruses have intensively circulated in the region in the past. Knowledge of the level of immune protection of the population for these mosquito-borne diseases is incomplete. For this purpose, seroprevalence studies that intend to retrospectively look for antibodies (IgG) as an evidence of previous infections by a specific pathogen would be highly informative. Knowing the serological profile of the Vanuatu population for dengue and other arboviruses as Ross River, chikungunya and Zika that could have affected the country in the past would be useful in defining the population likely to be infected by future epidemics. COVID-19 pandemic caused by SARS-CoV-2 as caused over 520 million cases since December 2019. Vanuatu has been relatively spared from the pandemic due to the establishment of a sanitary sas involving strict border control. On 04 March 2022, an active COVID-19 case was confirmed at Vila Central Hospital who had no travel history, indicating transmission at community level. Overall, a total of 8487 confirmed cases have been reported since the beginning of 2022. Local vaccination campaign was initiated in July 2021. A seroprevalence study documenting population immunity to COVID-19 will inform of the breadth of COVID-19 epidemic in Vanuatu, contributing to the evaluation of undetected infections rate. This identification of vulnerable populations will inform local public Health strategies, including targeted vaccination campaigns.

The goal of this clinical trial is to test whether In2Care EaveTubes (ETs) as a stand-alone tool can reduce malaria in an area where transmission is driven by insecticide-resistant Anopheles gambiae. Children who live in homes with ETs will be monitored for malaria infection and compared to children living in homes without ETs in Côte d'Ivoire where there is universal coverage of long lasting insecticide nets and pyrethroid resistance is high.

Background: Vector-borne diseases are caused by the bite of an infected mosquito, fly, flea, tick, or other blood-feeder. These diseases cause almost 1 million deaths per year. And they are on the rise, particularly in Southeast Asia in particular. Researchers think that these diseases make up about 10 percent of fevers in Cambodia. But many of these illnesses are never diagnosed. Studying these diseases can help find new ways to identify and treat them. Objective: To find pathogens in people who have a fever using metagenomic pathogen sequencing platforms. Eligibility: People aged 6 months to 65 years with a fever of at least 38 degrees Celsius who visit the referral hospital in Cambodia Design: Participants will be screened with their medical history. Children will be weighed to make sure they are big enough to give blood samples. Participants will share data about their sex, age, and where they live. They will answer more questions about their heath history. They will answer questions about and any places to which they have recently traveled. They will take a questionnaire. They will have a blood test. Participants aged 2 years or older who test positive for malaria will have one more blood test. Participation will last up to 2 days.

The primary objective of the study is to demonstrate and quantify the protective efficacy (PE) of spatial repellent products in reducing the incidence of malaria infection in human cohorts. The null hypothesis (H0) is that there is no difference in malaria incidence between intervention and control arms.

The purpose of this study is to evaluate the safety and immunogenicity of AGS-v PLUS, a universal mosquito-borne disease and mosquito control vaccine, in healthy volunteers.

Background: Mosquitos carry diseases that cause major health problems and death worldwide. The AGS-v vaccine targets proteins in mosquito saliva. This may help prevent many mosquito-borne diseases. It might also reduce the lifespan of the mosquito that bites the vaccinated person. Objective: To see if the AGS-v vaccine is safe in humans and how it affects the immune system. Eligibility: Healthy adults ages 18-50 Design: Participants will be screened another study. Participants will be randomly assigned to get either the vaccine with a booster vaccine, the vaccine without the booster, or a placebo. These are given through a needle in the upper arm. Participants will have visits that include medical history, physical exam, and blood and urine tests: Baseline: They will get the vaccine and be monitored for 2 hours. Follow-up visits 1 and 2 weeks after baseline. Visit 3 weeks after baseline: They will get the booster and be monitored for 2 hours. Follow-up visits 1 and 2 weeks after booster visit. Visit 3-5 weeks after booster visit: This includes mosquito feeding. Mosquitos grown in the lab will be allowed to bite the arm. Blood will be drawn 4 times in the 3 hours after the feeding. Phone follow-up a few days after the mosquito feeding. After the feeding visit, 5 follow-up visits about every 2 months Participants will keep a symptom diary for 7 days after each vaccine. They will record their temperature. They will measure any redness around the injection site. They will document and if possible photograph any mosquito bites they get.

Background: Mosquito-borne viruses like dengue cause major illness and death worldwide, particularly in Southeast Asia. When mosquitoes deliver a virus into the skin of humans, they also leave saliva. Researchers want to learn more about skin immunity to mosquito saliva. They hope this will help with future vaccines and treatments for these diseases. Objective: To compare the early and late innate immune response in the skin of Aedes aegypti bitten versus unbitten skin. Eligibility: Healthy people ages 18-45 who live within about 15 km of the study site in Chbar Mon Design: Participants will have 3 visits. The baseline/screening visit will include: Medical and medication history Questions about participants demographic information, mosquito biting risk factors, and responses to mosquito or other insect bites Physical exam Urine sample for some participants Mosquito feeding. A feeding device will be placed on the participant s arm for up to 20 minutes. The insects will feed through a mesh on the bottom of the feeding device. Participants may be given standard treatments for any skin reactions. Blood tests Four skin biopsies taken from bitten and unbitten skin. Local anesthetic will be administered, and a small tool will be used to remove the participant s skin. Participants will have a second visit the next day. They will have a physical exam and blood tests. They will have 1 skin biopsy. Participants will have a final visit about 2 weeks later. They will have a physical exam and blood tests. During the study, participants will be asked to take measures to prevent more mosquito bites.