Clinical Research Directory

Trial to Evaluate the Immunogenicity and Safety of the Co-administration of Live Attenuated Dengue and Chikungunya Vaccines Compared to Separate Administration in Adults Aged 18 to 59 Years.

This randomized, controlled, double blind trial aims at assessing the safety and immunogenicity profiles of the co-administered Live Attenuated Dengue and Chikungunya vaccines comparatively to the isolated administration, in the adult population aged 18 to 59 years without prior exposure to either arbovirus.

A Phase I Study of PepGNP-ChikV in Healthy Volunteers

This is a Phase I, randomized, single-blind, placebo-controlled, study of four separate dose cohorts, with a 42-day interval between each vaccine dose, of a novel Chikungunya Peptide Immunotherapy Vaccine in Healthy Adults (18-60 years of age). All participants will undergo a screening visit scheduled for a maximum of 28 days before the enrolment in the clinical study and will provide a blood sample for clinical laboratory tests (complete blood count (CBC)\*, platelet count, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, serum creatinine and activated partial thromboplastin time (aPTT), human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV)), and a urine sample for tests for Urinary protein, Urinary blood, Urinary glucose and human chorionic gonadotropin β-subunit (βhCG) urine test (only the female participants)) in order to confirm their eligibility for participation in the study. A total of 40 participants are planned to be enrolled. A randomization system will be used to assign treatment group and participant number at the clinical site. Participants will receive 2 injections, 42 days apart. A final visit will take place at Day 407 (i.e. 365 days after last vaccination). Participants will be kept under observation for 30 minutes after each vaccination to ensure their safety. Reactogenicity data will be collected in all participants after each vaccine injection: solicited injection site reactions will be collected for Days 0-10 and Days 42-52 and solicited systemic reactions will be collected for Days 0-21 and Days 42-63. Unsolicited events will be collected for Days 0-52. Serious adverse events (SAEs) will be reported throughout the study (from inclusion until 12 months after last vaccination). Serious and non-serious medically attended adverse events (MAAEs) and adverse events of special interest (AESIs) will be collected throughout the study (from inclusion until 12 months after last vaccination).

Risk Assessment of Community Spread of Multiple Endemic Infectious Diseases in a One Health Perspective

RACSMEI addresses the high burden of infectious diseases in low- and middle-income countries, including Cambodia, where limited surveillance and laboratory capacity often obscure etiologies and transmission dynamics. This knowledge gap hinders the design of effective prevention and control strategies. RACSMEI will improve understanding across multiple pathogens using a multidisciplinary One Health approach. We will answer key questions on burden, ecology, transmission and population immune status to inform targeted and culturally appropriate interventions. The project combines a nationally representative One Health survey, social-science methods, and multiplex, diverse diagnostics to efficiently test for 57 priority pathogens, including zoonotic and vector-borne agents, vaccine-preventable and elimination-targeted diseases, enteric, respiratory, and environmentally transmitted pathogens and selected neglected tropical diseases and parasites relevant to Cambodia. Mathematical modelling will reconstruct and forecast transmission dynamics and assess the potential impact of future public-health strategies. By integrating intersectoral data and innovative methods, RACSMEI will generate actionable evidence for public-health authorities, support precision One Health interventions, and help reduce disease burden in affected communities. The project also aims to ensure the transferability of methods and insights to other countries facing similar challenges.

Prospective Clinical Registry for Evaluation of Exanthematous Infections and Coinfections

Exanthematous fevers are a global public health problem. The spread of arboviruses due to various factors, including climate change, has resulted in major epidemics such as the one that occurred in Brazil in 2024, representing an extremely concerning scenario from both epidemiological and healthcare perspectives. In addition to this, the reemergence of childhood exanthematous diseases in several countries, including Brazil, is alarming and occurs due to declining vaccination coverage and increased migratory movements. These diseases present overlapping clinical symptoms, and their differential diagnosis is often challenging, which, in a context of dengue and Chikungunya epidemics like the current one, may lead to underreporting of diseases such as measles and rubella. This project aims to build a prospective registry of the occurrence of dengue, Chikungunya, measles, and rubella in various healthcare centers in Brazil, in order to better understand the epidemiological scenario, identify clinical variables associated with different diagnoses, and describe healthcare bottlenecks that may hinder proper reporting and identification of these diseases.

Virological and Immunological Determinants of Arbovirus Infection in New Caledonia

Arboviruses, diseases transmitted to humans by the bite of an insect vector, are a major public health problem, particularly in tropical and sub-tropical countries. In New Caledonia, dengue epidemics are recurrent and may be associated with the co-circulation of other arboviruses such as Zika or chikungunya. The virological determinants which condition the occurrence of these epidemics may be linked to an increased vectorial competence of the vector mosquito Aedes aegypti for a particular viral isolate. In fact, the Aedes aegypti mosquito is infected by making a blood meal on a person infected with an arbovirus. The virus infects its digestive tract, then spreads throughout the mosquito's body until it reaches its salivary glands. The virus is then present in the saliva and will be injected into the human host during a new blood meal. Some viral variants are best transmitted by Aedes aegypti. In general, the study of this vectorial competence is carried out by experiments in the laboratory during which an artificial blood meal composed of mammalian blood (human, rabbit, etc.) is mixed with a viral stock. Carrying out deported blood meals during which blood collected from patients infected with an arbovirus is used to gorge mosquitoes makes it possible to place oneself in experimental conditions as close as possible to the natural cycle of transmission of arboviruses. In the human host, cells of the myeloid lineage present in the peripheral blood constitute preferred targets of replication for arboviruses. At the same time, the peripheral blood cells of patients are activated in response to infection and secrete many soluble factors released into the blood of patients. The study of blood samples from patients infected with arboviruses is therefore of prime importance for understanding both the replicative mechanisms of arboviruses but also the immune response they induce.

Genetic Evolution of Arboviruses in New Caledonia Between 1995 and 2024 and Impact of Wolbachia

Arboviruses, diseases transmitted to humans by the bite of an insect vector, are a major public health problem, especially in tropical and sub-tropical countries. A promising strategy aimed at blocking the circulation of arboviruses is to release Aedes aegypti mosquitoes carrying the endosymbiotic bacterium Wolbachia. In 2019, the Wolbachia strategy was implemented in Nouméa as part of the World Mosquito Program. This intervention will modify the epidemiological profile of arboviruses in New Caledonia. Epidemiological surveillance of arboviruses requires molecular characterization of the virus contained in the serum obtained from the blood collected from patients. This molecular characterization by RNA isolation techniques, RT-qPCR monitoring and sequencing allows the construction of phylogenetic trees. In the context of the implementation of the World Mosquito Program in Nouméa, the investigators plan to follow the molecular evolution of arboviruses, over the period preceding the releases of mosquitoes carrying Wolbachia (from 1995 to 2019) then over a period of 5 years. following the releases. At the same time, the virus can be isolated by cell culture techniques and in vitro infections, allowing its study in vitro in cells or in vivo in mosquitoes. This study allows us to measure the impact of the Wolbachia strategy on the evolution of the virus's ability to replicate in cells in the presence of Wolbachia and to be transmitted by the mosquito.