Dengue prevention advocates and medical experts are pointing to fresh long-term evidence showing that a second-generation dengue vaccine can deliver sustained protection years after vaccination, a development that could strengthen the region’s fight against one of Asia’s most persistent public health threats.
In its November Dengue Policy Updates, the Asia Dengue Policy Working Group highlighted the final seven-year results of a major global clinical trial evaluating TAK-003, a dengue vaccine developed by Takeda. The data came from the Phase 3 Tetravalent Immunization against Dengue Efficacy Study, or TIDES, one of the largest and longest dengue vaccine trials conducted to date.
According to the update, completion data from the seven-year study showed that the standard two-dose regimen of TAK-003 provided sustained protection against virologically confirmed dengue, including severe cases and hospitalizations. An exploratory analysis also examined whether a booster dose could further enhance protection, but results suggested that the original two-dose schedule already delivers durable benefits—an important finding that could simplify vaccination programs and improve adherence.
Local vaccine experts welcomed the findings, particularly for dengue-endemic countries like the Philippines. Philippine Foundation for Vaccination executive director Dr. Lulu Bravo said the extended follow-up adds weight to the vaccine’s evidence base.
“These seven years of trial data have shown good safety results and protection against hospitalization and severe dengue,” Bravo said. “That gives us more confidence in the evidence.”
In the booster analysis, a subset of participants received an additional dose 4.5 years after completing the two-dose series. Over a 25-month follow-up period, protection against dengue was slightly higher among those who received the booster at 74.3 percent, compared with 61.2 percent among those who did not. Protection against dengue-related hospitalization, however, remained high in both groups—90.6 percent with the booster and 84.1 percent with the standard regimen—suggesting that two doses may be sufficient for long-term protection. Researchers also reported no new safety concerns, even after administration of the booster.
Bravo underscored that such conclusions are only possible because vaccines undergo rigorous, closely monitored clinical trials. She stressed that safety is the non-negotiable starting point in vaccine development.
“The first principle with vaccines is that it should not do harm,” she said, noting that large, well-audited trials and strict regulatory inspections are designed to ensure reliability and public trust. Final decisions on vaccine use, she added, ultimately rest with national regulators such as the Philippine Food and Drug Administration.
The discussion comes as dengue continues to exact a heavy toll. Worldwide, the mosquito-borne disease causes millions of infections each year. In the Philippines alone, Department of Health surveillance recorded 234,855 dengue cases and 912 deaths from January to September 20, 2025, underscoring the urgency of more effective prevention strategies.
Dr. Erica Tania Davillo, chair of the dengue committee of the Philippine Medical Association, acknowledged the government’s ongoing efforts in vector control but said vaccination could play a complementary role.
“A safe and effective vaccine can help our country reduce the dengue burden, as part of an integrated dengue prevention and control program,” she said.
Globally, TAK-003 has been studied in more than 20,000 participants across dengue-endemic regions, including the Philippines. Since its first regulatory approval in 2022, the vaccine has been authorized in several countries in Asia, Latin America, and Europe, with millions of doses already distributed. It is not yet available locally and remains under regulatory review.
Beyond efficacy data, experts also see encouraging signs when it comes to public trust. Bravo noted that vaccine confidence among Filipinos has been rebounding, citing forthcoming findings from the Vaccine Confidence Project that place the Philippines among the highest globally in confidence toward both vaccination in general and dengue vaccines in particular.
“The Philippines was topping vaccine confidence—85 percent for dengue vaccine and 88 percent for vaccination overall,” she said, adding that these figures outpace those of several countries in the Asia-Pacific region and Latin America.
Both Bravo and Davillo stressed that vaccination should not replace existing measures but strengthen them. Integrated approaches—combining vector control, community education, and access to safe vaccines—remain essential if the country hopes to reduce severe cases and deaths.
“There is an opportunity for us to end dengue deaths by 2030,” Davillo said. “But we need to work together, backed by accurate scientific information. We must fight disinformation and fear with evidence-based dengue prevention strategies, including vaccination.”
