Safety of and Immune Response to a Dengue Virus Vaccine (rDEN3delta30/31‐7164) in Healthy Adults

More than 2 billion people living in tropical and subtropical regions of the world are at
risk of dengue virus infection. Dengue viruses cause dengue fever, as well as the more
severe dengue hemorrhagic fever/shock syndrome, and dengue virus infection is the leading
cause of hospitalization and death in children in several tropical Asian countries. This
study will evaluate the safety and immunogenicity of a live, attenuated dengue virus called
rDEN3delta30/31‐7164.

This study will consist of two groups, with Group 1 enrolling first. Group 1 participants
will be randomly assigned to receive either 10^3 PFU of rDEN3delta30/31-7164 or placebo
subcutaneously in their deltoid. Participants will be monitored at the clinic for 30
minutes after receiving the immunization to monitor for adverse effects. After that,
participants will be asked to return to the clinic approximately every other day for the
next 16 days, and then on Day 21, 28, 42, and 180. At each visit participants will have
physical and clinical exams, vital signs, measures, blood drawn, and will be asked about any
adverse events they may have experience. Female participants will be given a pregnancy
test. In addition, participants will be asked to measure their temperature 3 times a day
and record it in a temperature diary for the first 16 days after immunization.

If less than 90% of the participants in Group 1 seroconvert to DEN3 then Group 2A will be
enrolled. Group 2A will follow the same procedures as Group 1, but will receive a 10^5 PFU
dose of rDEN3delta30/31-7164.

If more than 90% of the participants in Group 1 seroconvert to DEN3 then Group 2B will be
enrolled. Group 2A will follow the same procedures as Group 1, but will receive a 10^1 PFU
dose of rDEN3delta30/31-7164.