To evaluate the effectiveness of candidate dengue vaccine formulations, it is prudent to develop an appropriate challenge model. This study supports the expansion of the data set of the current Dengue 1 Live Virus Human Challenge (DENV-1-LVHC) model to produce uncomplicated dengue-like illness.

This is an expansion of a previous study conducted under NCT02372175. In this study up to nine healthy subjects between 18 and 45 years old will be inoculated with Dengue 1 Live Virus Human Challenge (DENV-1-LVHC) at a dose used in the previous study. Subjects will be closely monitored for the first 28 days with continued follow up through 6 months. Clinical and laboratory parameters, viremia and antibody levels will be assess. The goal is to expand the data set of symptoms produced by uncomplicated dengue-like illness.

Inclusion Criteria:

1. Age 18-45 at the time of consent
2. Ability and willingness to sign informed consent
3. Passing score on comprehension test of at least 75%, with up to 3 attempts
4. Available for the study period
5. Willing to use contraception for the duration of the study
6. Provide consent for release of medical history records from primary care physician, college or university, urgent care or emergency room visit

Exclusion Criteria:

1. Female: pregnant or lactating
2. Heavy menstrual bleeding within the last 6 months- menstrual periods lasting longer than 6 days, or requiring 5 or more pads or tampons per day.
3. Female subjects using an intrauterine device (IUD) or Mirena®
4. Female subjects with fibroids or uterine polyps, endometriosis, adenomyosis, and uterine scarring (e.g., after D&C)
5. Blood tests confirming infection with human immunodeficiency virus- 1 (HIV-1), hepatitis C, hepatitis B (assessed by HbsAg) virus, or positive antibodies to the flaviviruses (FV) dengue, West Nile, Yellow Fever, Japanese encephalitis, or Zika.
6. Active Diabetes or active peptic ulcer disease (PUD)
7. Chronic obstructive pulmonary disease (COPD) or coronary artery disease (CAD)
8. Known or suspected congenital or acquired immunodeficiency; or receipt of immunomodulation therapy such as anti-cancer chemotherapy or radiation therapy; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
9. Current, or a history of, auto-immune disease
10. History of Guillain-Barré syndrome (GBS)
11. Any history of FV infection or FV vaccination; or planned FV vaccination, outside the study protocol, during the study period
12. Diagnosis with Bipolar Disorder or Schizophrenia, hospitalization in the past year for a mental health disorder, or any other psychiatric condition, which in the opinion of the investigator prevents the subject from participating in the study.
13. Planned travel during the study period (180 days) which would interfere with the ability to complete all study visits
14. Recent (in the past 4 weeks) travel to any dengue endemic area. These potential subjects may be eligible for enrollment a minimum of 4 weeks later
15. Any grade 2 laboratory abnormalities prior to inoculation for the tests specified in Table 18 and Table 19 of the protocol, except those listed in exclusion criteria 16
16. Subjects with the following grade 1 or greater lab abnormalities: Creatinine; Liver Function Tests - ALT, AST; Hemoglobin (females and males); White Blood Cell (WBC) decrease; Platelets decreased; Prothrombin Time (PT); Partial Thromboplastin Time (PTT); Fibrinogen decrease
17. Significant screening physical examination abnormalities at the discretion of the investigator
18. Women who intend to become pregnant or men who intend to father a child during the study period (approximately 180 days)
19. Hives, shortness of breath, swelling of the lips or throat, or hospitalization related to a previous vaccination or an allergy to specific medications/animals for which antigens may be in the virus preparations to include: shellfish allergy, fetal bovine serum, L-glutamine, neomycin and streptomycin
20. Planning to donate blood in the 1 year following inoculation with dengue
21. Recent blood donation within prior 56 days of inoculation
22. Receipt of blood products or antibodies within 56 days of inoculation or during the study period
23. Participation (active or follow-up phase) or planned participation in another vaccine, drug, medical device, or medical procedure clinical trial in the 4 weeks prior to this trial, during the trial, or 6 months following inoculation in this clinical trial
24. Recent or scheduled receipt of any vaccine 4 weeks prior to or after virus inoculation
25. Beliefs that bar the administration of blood products or transfusions
26. Positive urine screen for cocaine, amphetamines, or opiates
27. Currently taking Methadone or Suboxone
28. Currently taking anti-coagulant medication, aspirin or non-steroidal anti-inflammatory drugs (NSAIDs)
29. Chronic migraine headaches, defined as more than 15 headache days per month over a 3 month period of which more than 8 are migraines, in the absence of medication over use
30. Chronic medical condition that, in the opinion of the investigator, impacts subject safety.