A Controlled Human Infection Model of Dengue
This study aims to conduct a safe human infection challenge using an attenuated serotype DEN3 dengue virus in adult volunteers. The clinical, viral and immune response characteristics of the model will be analysed to understand the pathophysiology of dengue fever. This data will be used to inform future studies, including a planned follow up study (DEN-CHIM-02) which will investigate the efficacy of an investigational dengue vaccine at protecting against DEN3 infection. Study conditions that result in a safe, reproducible infection in ≥80% of research participants (attack rate) with the DEN3 challenge agent have been identified during studies conducted by our collaborators in the US. This includes the inoculum dose, safety monitoring, and necessary participant pre-screening to exclude prior Orthoflavivrus infection or vaccinations. Study objectives are to: 1. Establish in seronegative volunteers in Singapore a safe DENV controlled human infection (CHI) model, with an infection rate of ≥80%, suitable for future studies of interventions. 2. Characterise the clinical, haematological and virological response following controlled inoculation of the attenuated DEN3 challenge agent. 3. Conduct deep immunophenotyping to understand the cellular, humoral and innate immune response to dengue infection. 4. Explore the longitudinal immune response in the 3 years after challenge, including following subsequent dengue vaccination.
• An informed consent form (ICF) has been signed and dated by the participant, an investigator, and a witness
• Adult, aged between 21 and 45 years, inclusive (at the time of consent)
• No known history of prior dengue, zika or other Orthoflavivirus infection
• No history of prior dengue, yellow fever, Japanese encephalitis virus, or other Orthoflavivirus vaccination
• Sero-suitable based on the pre-screening serology result
• a Female participants must be willing and able to use contraception from 2 weeks before the scheduled date of viral challenge until 1 month after receipt of the final dose of study virus. Negative urine pregnancy tests will be required at screening, and on admission to the quarantine unit a negative serum beta human chorionic gonadotropin (β-hCG) is required prior to inoculation.
⁃ 6b Male participants who are willing to use one of the contraception methods described in the study protocol, from the date of viral challenge, for 1 month. In addition to the contraceptive requirements above, male participants must agree not to donate sperm following discharge from quarantine until 1 month after the date of viral challenge.
⁃ 7 In good health with no history of clinically significant medical conditions (as described in Exclusion criteria) that would interfere with subject safety, as defined by medical history, physical examination and routine laboratory tests, ECG, and Chest X-Ray and determined by the Investigator at an admission evaluation.
⁃ 8 Willing and able to commit to participation in the study.