Takeda Pharmaceutical Company Limited has reported positive seven-year results from its pivotal Phase 3 TIDES trial evaluating the company's dengue vaccine, QDENGA, confirming its durable protection against dengue infection. The findings, which included an exploratory booster analysis, reinforce that the two-dose regimen offers sustained efficacy against the mosquito-borne disease.
Long-Term Efficacy Results
During the TIDES study (NCT02747927), two doses of the live, attenuated vaccine prevented virologically confirmed dengue (VCD) in 61.2% of participants 4.5 years after dosing. The vaccine's benefits were observed against all four serotypes of the dengue virus across the seven-year study period.
QDENGA also demonstrated significant protection against severe outcomes, reducing dengue-related hospitalizations by 84.1% at the 4.5-year mark. Vaccine efficacy remained consistently high at 90.6% overall across all four dengue virus serotypes.
Booster Dose Analysis
After the initial 4.5-year study period, patients randomized to the QDENGA arm were given a booster dose of the vaccine. While the booster dose enhanced QDENGA's effectiveness, this impact was only marginal, as the vaccine demonstrated 74.3% effectiveness two years following booster administration.
No new safety concerns were observed following the booster dose administration during the latter portion of the TIDES study.
Global Health Context
The positive results come amid a sharp rise in dengue fever prevalence worldwide, with more than 14 million cases and 9,508 deaths reported in 2024 alone. According to Edson Moreira, senior researcher at the Brazilian Ministry of Health's Oswaldo Cruz Foundation, the surge in dengue cases is primarily driven by both "inadequate urbanization" and climate change.
Moreira noted that dengue is particularly prevalent in Brazil, which accounted for just under 50% of all reported dengue cases in the Americas in 2024. He emphasized there is an "urgent need for dengue prevention methods" as dengue has presented a significant issue to global healthcare systems, especially in the Southern hemisphere.
Market Authorization and Distribution
Since its first approval in Indonesia in 2022, QDENGA has been authorized in 41 countries, with more than 18 million doses distributed across 11 endemic regions as of September 2025. The vaccine has also earned a place on the World Health Organization's (WHO) list of prequalified vaccines in May 2024.
US Market Challenges
Despite its widespread market penetration, QDENGA has yet to debut on the US market. Takeda withdrew its application to the US Food and Drug Administration (FDA) for the vaccine in 2023 after regulators raised issues with the TIDES study's data collection process.
The US dengue vaccine market has seen limited success, with Sanofi's Dengvaxia being the only dengue vaccine to obtain FDA approval in 2019. However, Sanofi will discontinue the drug by Q3 2026 due to "a lack of demand on the global market."
Commercial Outlook
Despite market challenges in some regions, analysts at GlobalData forecast that Takeda's QDENGA will earn blockbuster status in 2031, pulling in $1 billion in global sales during the year.
