The vaccine tested in this Pase 3 study is TDV also known as TAK-003 (DENVax). TDV with concomitant and sequential administration of yellow fever (YF-17D) vaccine will be tested to assess immunogenicity and safety in healthy adult participants in non-endemic area(s) for both dengue and YF.

The study will enroll 900 healthy participants. Participants will be randomized to 3 groups in 1:1:1 ratio and will be administered concomitantly and sequentially. The 3 groups are:

Group 1: YF-17D vaccine + placebo concomitantly administered on Day 1, first dose of TDV administered on Day 90 and second dose of TDV administered on Day 180.

Group 2: first dose of TDV + placebo concomitantly administered on Day 1, second dose of TDV administered on Day 90 and YF-17D vaccine administered on Day 180.

Group 3: first dose of TDV + YF-17D vaccine concomitantly administered on Day 1, second dose of TDV administered on Day 90 and placebo administered on Day 180.

This multi-center trial will be conducted in the United States. The overall time to participate in this study is 360 days. Participants will make multiple visits to the clinic with a 6-month follow up including a final visit at Day 360 for a follow-up assessment.