Long-Term Safety and Antibody Persistence of TDV and the Impact of a Booster Dose

Exclusion Criteria

• •1. Participants with a prolonged period of habitation (≥1 year) in a dengue endemic area within the 2 years prior to Visit 1 Day 1 (Month 0).
• •2. Previous and planned vaccination (during the trial conduct), against any flavivirus including dengue (other than Takeda's TDV), yellow fever (YF), Japanese encephalitis (JE) viruses or tick-borne encephalitis.
• •1. Participants for whom baseline serostatus is not defined in the parent trials (DEN-304 \[(NCT03423173)\] and DEN-315 \[NCT03341637\]).
• •2. Participants with any history of progressive or severe neurologic disorder, seizure disorder or neuro-inflammatory disease (eg, Guillain-Barré syndrome).
• •3. Known or suspected impairment/alteration of immune function, including:
• •1. Chronic use of oral steroids (equivalent to 20 mg/day prednisone ≥12 weeks/≥2 mg/kg body weight/day prednisone ≥2 weeks) within 60 days prior to Month 42 for participants from parent trial DEN-315 (Mexico)/ Month 15 for participants from parent trial DEN-304 (US); use of inhaled, intranasal, or topical corticosteroids is allowed.
• •2. Receipt of parenteral steroids (equivalent to 20 mg/day prednisone ≥12 weeks/≥2 mg/kg body weight/day prednisone ≥2 weeks) within 60 days prior to Month 42 for participants from parent trial DEN-315 (Mexico)/ Month 15 for participants from parent trial DEN-304 (US).
• •3. Administration of immunoglobulins and/or any blood products within the 3 months prior to administration of the TDV booster or placebo at Month 42 for participants from parent trial DEN-315 (Mexico)/ Month 15 for participants from parent trial DEN-304 (US); consider whether applicable as an exclusion criterion or criterion for delay.
• •4. Receipt of immunostimulants within 60 days prior to Month 42 for participants from parent trial DEN-315 (Mexico)/ Month 15 for participants from parent trial DEN-304 (US).
• •5. Immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within 6 months prior to Month 42 for participants from parent trial DEN-315 (Mexico) / Month 15 for participants from parent trial DEN-304 (US).
• •6. Known human immunodeficiency virus (HIV) infection or HIV-related disease.
• •7. Hepatitis C virus infection.
• •8. Genetic immunodeficiency.
• •4. Abnormalities of splenic or thymic function.
• •5. Participants with a known bleeding diathesis, or any condition that may be associated with a prolonged bleeding time.
• •6. Participants with history of current or previous infection with a flavivirus such as dengue, Zika, YF, JE, West Nile fever, tick-borne encephalitis or Murray Valley encephalitis and participants with a prolonged period of habitation (≥1 year) in a dengue endemic area during trial conduct.