There are a few approved vaccines for dengue, but they are only available in certain parts of the world and do not provide full protection for everyone. Dengue symptoms may not appear for several days after infection. By the time a person sees a doctor, the early stages of infection are usually over. This is why it is important to better understand dengue—especially what happens in the early stages and in the months that follow—to help develop new vaccines and medicines. In addition, many current studies do not have the resources to follow participants for 6 to 12 months, even though this long-term follow-up is important for understanding how the immune system responds. This study aims to address some of these gaps.

You may be eligible for this study if you meet the following criteria.

Inclusion Criteria:

• Individuals who have lived in or traveled to areas where dengue is common, OR have never traveled to those areas
  • Areas where the dengue virus is common, including, but not limited to:
    • Southeast Asia (e.g., Thailand, Vietnam, Philippines, Indonesia)
    • South Asia (e.g., India, Pakistan, Sri Lanka, Bangladesh)
    • East Asia (e.g., China, Taiwan, Hong Kong)
    • Sub-Saharan Africa (e.g., Nigeria, Kenya, South Africa, Madagascar)
    • Caribbean (e.g., Puerto Rico, Cuba, Jamaica, Dominican Republic)
    • Central America (e.g., Mexico, Costa Rica, Panama)
    • South America (e.g., Brazil, Colombia, Peru, Venezuela)
    • Oceania / Pacific Islands (e.g., Fiji, Samoa, Tonga, Northern Australia)
    • Middle East (e.g., Yemen, Saudi Arabia, Oman)
• Willing to receive a weakened version of the virus
• Able to participate in this study for at least 6 months (up to 12 months) with in-person visits in Bethesda, MD
• If applicable, be willing to use a medically accepted form of birth control for the first 3 months of study participation
• Agree to avoid getting any vaccines for at least the first 2 months of study participation
• Willing to allow storage of samples and data for future research
• Ages 18 – 50 years 

Exclusion Criteria:

• No clinically significant immune diseases, asthma, hypertension, or diabetes
• No history of HIV, hepatitis B, or hepatitis C
• Not currently pregnant or breastfeeding

There are 11 required study visits at the NIH Clinical Center, with the study lasting at least 6 months and up to 12 months. Eight of these visits are in the first month. There are also optional visits up to 2 months before the challenge and 1 year after.

The challenge virus is injected into the fatty tissue just under the skin of your upper left arm, like the flu shot.

Study visits will include:

• checking your vital signs (temperature, pulse, breathing rate, and blood pressure)
• physical exam
• reviewing your medical and medication history
• taking blood (between 2 and 10 tablespoons)
• asking you about side effects or discomforts you have had since receiving the challenge virus
  
  

For some visits, you will only come in for a blood draw. We will then follow up with you by phone, telehealth, or secure email to ask about any side effects, health concerns, or changes to your medications.

Two or three times during the study, you will fill out a detailed survey about your recent travel and possible exposure to other viruses.

There are three optional procedures. If you agree, an ultrasound may be used to look for any changes in your chest and abdomen. Lymph node aspiration and bone marrow biopsy can also be performed. Both collect immune system cells so we can see how your body responds to the challenge virus. We may take photos of your skin before you receive the weakened dengue virus and again, if a rash appears, to record skin changes.

As part of this study, you will learn whether you have ever had dengue. If you have, you may also learn which type of dengue virus you had.

Compensation is between $1645 and $3695 for study completion. 

There is no cost for you to participate in our research study.