KUALA LUMPUR, Nov 21 — Controlling dengue requires a sustained, continuous effort that combines reducing virus transmission with maintaining population immunity through vaccination, say experts.
At an Asia Pacific regional media roundtable on November 6, Prof Ooi Eng Eong, a professor in emerging infectious diseases at Singapore’s DUKE-NUS Medical School, said infectious diseases aren’t constant throughout the year.
“Everything happens in cycles depending on a number of things, particularly the infectivity or the rate of transmission of the virus. Therefore, the short answer to controlling dengue is – you cannot rest,” Ooi told the virtual media roundtable.
“Because if you do, then the interval between the epidemics comes back sooner and if you have gotten an infection in between these epidemics, then your risk of acquiring severe disease during an epidemic goes up.”
Ooi highlighted the complex role of vaccination in sustaining immunity at a population level.
“With mosquito control, you reduce transmission. When you reduce transmission, as we learn during Covid, you don’t have immunity, right? And when you do have an epidemic, the population’s very susceptible to disease and potentially severe disease,” he said.
“So regardless of whether you’re reducing the mosquito population or you’re using Wolbachia, the end result is that the population immunity goes down.
“Therefore, the solution is that you reduce transmission but sustain population immunity. And the only way [you] can do that is through vaccination.”
Ooi stressed the importance of vaccinating adults, especially those with chronic health conditions.
“If adults are getting dengue, and particularly those that are living with chronic diseases like diabetes, heart disease, hypertension and all that, which are very common, then actually vaccination benefits that population and there, you don’t need to wait to have high transmission rate,” he said.
“Because they can get the severe disease even in between outbreak periods. In fact, several studies now show that in the 12 months after an adult gets dengue, their chances of dying from a heart disease, from a stroke, or from an event unrelated to dengue is much higher compared to a person that hasn’t gotten dengue.”
Addressing vaccine hesitancy, Ooi stressed the necessity and importance of using available vaccines today.
“What we have – one that has been licensed and one that has completed one Phase Three clinical trial – are probably all that we’re going to have for the next 30 to 40 years, so we should learn to make use of what we have now, rather than wait and say we need a perfect solution and disregard what can work.”
Takeda global vaccine president Dr Derek Wallace described the company’s focus on vaccine distribution in dengue-endemic countries.
“Ninety-five per cent of our doses have gone to endemic countries and three quarters of those doses have been distributed through public programmes, which for us is the best way to ensure equity in availability of a vaccine,” said Dr Wallace at the regional media roundtable.
He also emphasised the importance of government involvement in vaccine accessibility.
“That’s why our priority is in working with those governments who are early adopters of public programmes.”
Dr Wallace said data over seven years shows that Takeda’s dengue vaccine is safe and shows sustained protection against hospitalisation from all four dengue serotypes.
He noted shifts in public perception shaped by recent vaccination campaigns, adding that one of the positives is an understanding of the use of a vaccine across a broader age range for life-course vaccination.
“Dengue is a disease that doesn’t just affect young children, it also affects the adult population and even elderly. Covid has enabled mechanisms to vaccinate across an age range.”
Dr Wallace described Takeda, a large pharmaceutical company that has been around for more than 240 years, as having a very strong focus on public health.
“We are very proud to be working on combating dengue, a disease that has such a huge global impact affecting half the world’s population and is one of the World Health Organization’s (WHO) top 10 threats to public health.”
Dr Mahender Nayak, senior vice president of Asia Pacific countries at Takeda, talked about a broader health system approach beyond vaccines.
“To pre-empt future global health threats, in addition to discovering new treatments and vaccines, we need to explore how existing medicines and vaccines can be delivered equitably and sustainably,” he told the media roundtable.
“Dengue doesn’t respect borders and neither should our response. Strong regional collaboration across countries, sectors, and institutions is essential to improving preparedness and protection. Through public–private partnerships, we can help ensure vaccines reach those who need them most, strengthen community awareness, and support health systems to better respond to future outbreaks.”
Dr Nayak also spoke about how Indonesia pioneered the introduction of the dengue vaccine, with a provincial immunisation programme across five provinces.
“There’s tremendous opportunity for shared learning among countries where the vaccine is approved.”
On vaccine hesitancy and health system readiness, Dr Nayak said education is only the first step.
“Working with academia and policymakers ensures people have the right information to make informed decisions. Equally important is strengthening health systems through training, infrastructure, and cold-chain capacity so vaccines reach people equitably. We can’t be complacent and wait for the next outbreak – continuous collaboration is key to preparedness.”
The regional media roundtable discussed how dengue control needs sustained and continuous effort, leveraging vaccination to maintain immunity, targeted strategies for at-risk populations, and strong regional collaboration.