López-Medina E.Biswal S.Saez-Llorens X.Borja-Tabora C.Bravo L.Sirivichayakul C.Vargas L.M.Alera M.T.Velásquez H.Reynales H.Rivera L.Watanaveeradej V.Rodriguez-Arenales E.J.Yu D.Espinoza F.Dietze R.Fernando L.K.Wickramasinghe P.Duarte Moreira E.Fernando A.D.Gunasekera D.Luz K.Da Cunha R.V.Tricou V.Rauscher M.Liu M.Lefevre I.Wallace D.Kosalaraksa P.Borkowski A.Mahidol University2023-06-182023-06-182022-05-01Journal of Infectious Diseases Vol.225 No.9 (2022) , 1521-153200221899https://repository.li.mahidol.ac.th/handle/20.500.14594/85948Background: Takeda's dengue vaccine is under evaluation in an ongoing phase 3 efficacy study; we present a 2-year update. Methods: Children (20 099, 4-16 years old) were randomized to receive 2 doses of TAK-003 or placebo 3 months apart and are under surveillance to detect dengue by serotype-specific RT-PCR. Results: Cumulative efficacy against dengue approximately 27 months since first dose was 72.7% (95% confidence interval [CI], 67.1%-77.3%), including 67.0% (95% CI, 53.6%-76.5%) in dengue-naive and 89.2% (95% CI, 82.4%-93.3%) against hospitalized dengue. In the second year, decline in efficacy was observed (56.2%; 95% CI, 42.3%-66.8%) with the largest decline in 4-5 year olds (24.5%; 95% CI, -34.2% to 57.5%); efficacy was 60.6% (95% CI, 43.8%-72.4%) in 6-11 year and 71.2% (95% CI, 41.0%-85.9%) in 12-16 year age groups. As TAK-003 efficacy varies by serotype, changes in serotype dominance partially contributed to efficacy differences in year-by-year analysis. No related serious adverse events occurred during the second year. Conclusions: TAK-003 demonstrated continued benefit independent of baseline serostatus in reducing dengue with some decline in efficacy during the second year. Three-year data will be important to see if efficacy stabilizes or declines further.MedicineArticleSCOPUS10.1093/infdis/jiaa7612-s2.0-851078854491537661333319249