View clinical trials related to Vector-Borne Diseases.
Filter by:Malaria is a major public health problem. There were around 240 million cases of malaria and 627,000 deaths worldwide in 2020. Most of the deaths are in children under five living in Africa. It is a major problem for those who live in affected areas and for travellers. There is a great need for a safe, effective malaria vaccine. This study is being done to evaluate an experimental malaria vaccine for its safety and also look at the body's immune response to the vaccine. The vaccine tested in this study is called and "RH5.1". This is given with an adjuvant called "Matrix-M". This is a substance to improve the body's response to a vaccination. The aim is to use the vaccines and adjuvant to help the body make an immune response against parts of the malaria parasite. This study will assess: 1. The safety of the vaccines in healthy participants. 2. The response of the human immune system to the vaccines. This will be achieved by giving participants three doses of the RH5.1 vaccines at two different dose levels (10 micrograms and 50 micrograms). One group will have 3 doses of 10 micrograms given at 0, 1 and 6 months whilst the other will receive 2 doses of 50 micrograms (at 1 and 2 months) followed by a 10 microgram dose at 6 months- known as a 'delayed fractional dose'. Blood tests and information about any symptoms will be performed/collected that occur after vaccination. Information from previous studies suggests that a delayed fractional dose improves the immune response to the vaccine, particularly in terms of the antibody response. Current prediction is that this improvement is due to the delay in dosing, rather than the reduction in dose, and this study will help to answer that. Having a vaccine at a single dose is important for efficient production and dosing for vaccines rolled out in national programs so being able to move away from 'delayed fractional dose' regimens to 'delayed final dose' regimens will be important for vaccine development.
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: 1. The safety of the vaccine in healthy participants. 2. The response of the human immune system to the vaccine. 3. 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 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.
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 2 months to 65 years with a fever of at least 38 degrees Celsius or those diagnosed with infection by a pathogen of concern who visit the referral hospital in Cambodia. Close contacts of people diagnosed with infection by a pathogen of concern may also be enrolled. 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. If they have respiratory symptoms, they will have a nasal swab. Participants may be contacted within 1-2 weeks (early) and/or within 3 months (late) from their enrollment date to provide an optional follow-up blood samples and nasal swabs.