The urgent need for a licensed dengue vaccine in the Philippines

Dear Editor,

Dengue is a mosquito-borne flaviviral disease endemic to tropical and subtropical regions, affecting hundreds of millions worldwide. Although it was once considered a neglected disease, dengue’s incidence and mortality rates have surged over the past decade, partly due to the expanding distribution of the Aedes spp. vector facilitated by changing climatic factors. ¹ In the Philippines, the disease remains a serious public health issue, especially during the rainy season. There have been 52,008 cases recorded as of February 2025, compared to around 31,712 cases in 2024—marking an increase of 20,296 cases. ² Unfortunately, until now, no vaccine has been approved for use. The reason for the slow approval of a dengue vaccine stemmed from the Chimeric Yellow Fever-Dengue Tetravalent Dengue Vaccine (CYD-TDV) (Dengvaxia) controversy that was allegedly linked to the 1967 out of 3281 patients were found to have contracted dengue, and the death of 14 children who were given one to three doses of the vaccine. The country’s Food and Drug Administration (FDA) permanently withdrew the vaccine’s license in February 2019. ³ Though more investigations are being held, some government officials and social media have politicized and sensationalized the unofficial evaluation results, and this paved the way to the sudden halt of the immunization program against dengue.

Given this unfortunate experience, it is time to move on, and a licensed dengue vaccine is urgently needed as the situation gets worse yearly. However, the complexity of dengue vaccine hesitancy is foreseen as a significant barrier to a higher vaccine rollout in case of a possible vaccine availability. Thus, it needs to be addressed by considering strategies that are focused on ensuring safety concerns, enhancing public awareness, and improving vaccine affordability. ⁴ Aside from Dengvaxia, another vaccine that has high efficacy and is widely used in many countries is TAK-003 (QDENGA). A recent study assessed whether TAK-003 could protect against asymptomatic/subclinical infections by evaluating increased neutralizing antibody (NAb) titers after natural infection in 3765 participants. They concluded that TAK-003 had a modest impact on asymptomatic dengue infections in the first months post-vaccination, mainly in participants with baseline seropositivity. ⁵

Regarding safety concerns, the Takeda Pharmaceutical Company has already applied for a certificate of product registration of TAK-003 from the FDA in 2023. The company boasts of the vaccine’s enhanced safety quality, and many countries have already approved its use, like the European Union/European Economic Area and Great Britain, Indonesia, Brazil, Argentina, Colombia, Thailand, Malaysia, Vietnam, Israel, and Switzerland, among others. It has also been prequalified by the World Health Organization (WHO) for the prevention of dengue in children aged 6 years, and WHO-SAGE recommended that TAK-003 be considered for public programs in high-transmission areas for those aged 6–16 years, without prescreening. ⁵ These countries and the WHO have proven, in one way or another, the safety of this vaccine.

Regarding enhancing public awareness, the government must prepare and create strategies for a massive information program in case TAK-003 is approved, alongside its different initiatives on the prevention of dengue. In fairness to the country’s Department of Health (DOH), it established the National Dengue Prevention and Control Program. This aims to eliminate dengue infection by properly implementing an integrated vector control approach and reinforcing the diagnosis, management, and surveillance of dengue cases. The 5S strategy, the 4 o’clock habit, and the dengue fast lane are the three primary campaigns of the DOH. The 5S strategy encourages communities to search and destroy breeding sites, employ self-protection measures, seek early consultation, support fogging in hotspot areas, and sustain adequate hydration. The 4 o’clock habit refers explicitly to a stop, look, and listen approach, whereby one drops whatever is being done to search and destroy mosquito breeding sites. Dengue fast lanes in hospitals are implemented to ensure that suspected dengue patients are given immediate and proper medical intervention. ⁶ The “Alas-Kwatro Kontra Mosquito” drive was launched in February 2025. This campaign encourages families, schools, and workplaces to clean potential mosquito breeding grounds daily at 4:00 PM. It also involves “Taob, Taktak, Tuyo, Takip” as the four basic ways of cleaning and eliminating possible mosquito breeding grounds. With this, the DOH has noted the low case fatality rate (CFR) of 0.36%, or about four deaths per 1000 dengue cases. ⁷ The ASEAN Dengue Day is also observed and celebrated every June 15 as a regional advocacy initiative to raise awareness against dengue.

Lastly, concerning vaccine affordability, as the public waits for the approval of the TAK-003 vaccine, the government and the public must anticipate and be ready for its cost. The price of the vaccine in neighboring countries like Indonesia and Malaysia is around USD 80–143 (₱4500–8000) for the two required doses. This high cost will be a significant challenge for an ordinary Filipino. The average monthly salary in the Philippines is around ₱19,436. In a study conducted on 7193 respondents, only 21% were willing to pay an amount of ₱1000 (USD 20) for the COVID-19 vaccines. ⁸ Most locals will spend their earnings on food and their family’s basic needs rather than on vaccines. The government must anticipate this issue of vaccine affordability by allotting subsidies to address disparity and VH simultaneously.

Ensuring the vaccine’s safety concerns, enhancing public awareness, and improving vaccine affordability must be the non-negotiable components of a successful dengue vaccination program. Until when should Filipinos wait for an approved dengue vaccine? Since another alternative vaccine is already out, are the government and other institutions prepared enough to handle the challenges to come? We hope there is no more controversy. Let us not be part of the problem, but of the solution, for the sake of public health.