A Study of JNJ-64281802 Against Dengue Serotype 1 Infection in a Dengue Human Challenge Model in Healthy Adult Participants

A Phase 2a, Randomized, Double-blind, Placebo-controlled Trial to Evaluate the Antiviral Activity, Safety, and Pharmacokinetics of Repeated Oral Doses of JNJ-64281802 Against Dengue Serotype 1 Infection in a Dengue Human Challenge Model in Healthy Adult Participants

The purpose of this study is to assess the antiviral activity of JNJ-64281802 versus placebo in terms of reduction of dengue virus 1 (DENV-1) ribonucleic acid (RNA) viral load (VL).

Inclusion Criteria:

• Healthy on the basis of physical examination, medical history, and vital signs performed at screening. If there are abnormalities, the participant may be included only if the investigator judges the abnormalities to be not clinically relevant. This determination must be recorded in the participant's source documents and initialed and dated by the investigator
• Must pass the comprehension test (i.e., obtain a passing score of greater than or equal to (>=) 75 percent (%), with up to 3 attempts in total) indicating that he or she understands the purpose, procedures, and potential risks and benefits of the study, after reading the informed consent and after the investigator or designee has provided detailed information on the study and answered the potential participant's questions
• Must have a blood pressure (after the participant is supine for >=5 minutes) between 90 and 140 millimeters of Mercury (mmHg) systolic, extremes included, and less than or equal to (<=) 90 mmHg diastolic at screening. Two repeat measurements are allowed in the absence of any other concerning health screening issues
• Must have a Body mass index (BMI) (weight in kilogram divided by the square of height in meters) between 18.0 and 33.0 kilogram per meter square (kg/m^2), extremes included, and a body weight of >=50.0 kg at screening
• All women of childbearing potential must have a negative highly sensitive serum (beta-human chorionic gonadotropin) pregnancy test at screening

Exclusion Criteria:

• Known allergies, hypersensitivity, or intolerance to JNJ-64281802 or its excipients, to a previous vaccination, or to specific medications/animals for which antigens may be in the dengue virus (DENV)-1 challenge strain preparations, including shellfish, fetal bovine serum, L-glutamine, neomycin, and streptomycin
• Any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant (example, compromise the well-being) or that could prevent, limit, or confound the protocol-specified assessments
• Received an investigational intervention (including investigational vaccines) or used an invasive investigational medical device within 6 months before first dose of study drug, or is currently enrolled in an investigational study, or is planning to be enrolled in an investigational study within 90 days after last dose of study drug
• Pregnant, breastfeeding, or planning to become pregnant during the study or within 90 days after last dose of study drug
• Plans to father a child during the study or within 90 days after last dose of study drug