A new era in dengue prevention through vaccine innovation

Dion Warren, Area Head of India and Southeast Asia for Takeda has shared his insights about the impacts of Takeda's dengue vaccine for the health of the people of Viet Nam, and their upcoming plan to support strengthening the fight against dengue here.

Dengue fever is a rapidly escalating public health threat throughout Southeast Asia and now a global issue which threatens half of the world's population. Among the efforts to prevent dengue, proactive prevention methods to complement current measures are essential.

The global incidence of dengue fever has increased 30-fold over the past 50 years. Cases reached their highest number on record in 2023, with 6.5m reported globally - and the number of cases are estimated to double beyond that figure in 2024, with 13,3m cases reported so far this year.

In Viet Nam, a nation that has been listed as one of the most impacted from this disease by WHO, dengue fever is prevalent in almost all regions across the country. In 2022, Viet Nam recorded one of the highest dengue fever cases in the world with 360,000 cases, 5 times more than in 2021.

Climate conditions, unclean environments, unplanned urban settlements and rapid urbanization have exacerbated the spread of dengue fever by creating an ideal environment to increase mosquito breeding.

In a recent exclusive interview with VGP, Dion Warren, Area Head of India and Southeast Asia for Takeda, shared his insights about the impacts of Takeda's dengue vaccine for the health of the people of Viet Nam, and their upcoming plan to support strengthening the fight against dengue.

 Could you begin by explaining why dengue remains such a persistent threat in regions like Southeast Asia, and why a vaccine for dengue is needed now more than ever?

Dion Warren: Dengue is a complex disease that places a significant burden on public health, including in countries like Viet Nam, where the combination of a tropical climate and dense urban populations creates an ideal environment for its transmission. In recent years, the number of cases has been increasing due to climate change, which has exacerbated the spread of the disease. The Aedes mosquito, which spreads the virus, is incredibly resilient and difficult to control through traditional vector control methods alone. Additionally, because there are four distinct serotypes of the dengue virus, infection with one serotype only provides temporary immunity to that specific strain, leaving individuals vulnerable to re-infection from other strains of the disease.

The availability of a safe and effective dengue vaccine represents a critical addition to the arsenal of dengue prevention methods. While environmental and vector control measures are important, they have their limitations. A comprehensive approach, combining vaccination with other preventive measures such as environmental clean-up, vector control, and public awareness campaigns, offers the best chance to significantly reduce the incidence and severity of dengue fever. A vaccine offers a sustainable, long-term solution that can significantly reduce the number of cases of the disease and reduce severe cases that require hospitalization, thereby reducing the immense strain on healthcare systems each year.

How was dengue vaccine developed, and what were some of the key challenges in creating a vaccine that could protect against multiple dengue strains?

Dion Warren: As you know, dengue is a complex disease caused by four different virus serotypes (DENV-1, 2, 3 and 4), making vaccine development particularly challenging. The development of Takeda's dengue vaccine has a long and intricate history, dating back over 40 years.

While efforts to find a dengue vaccine began as early as the 1920s, significant progress remained elusive for many decades due to various obstacles. Our dengue vaccine journey traces back to 1978 at Mahidol University in Thailand.

The World Health Organization (WHO) Regional Office for Southeast Asia proposed a project for dengue vaccine research. Mahidol University was selected as a partner. The university led the dengue vaccine research and development and later in 1986, the university discovered a live-attenuated vaccine that prevents DENV-2. This became the crucial foundation for our current tetravalent vaccine. After many years of research, this effort culminated in creating a tetravalent vaccine capable of providing broad protection against all four dengue virus serotypes.

Over the past decade, under Takeda's leadership, the dengue vaccine successfully completed clinical development program involving 19 clinical trials, a total of 28,000 participants across 13 dengue-endemic and non-endemic countries. In 2024, Takeda's dengue vaccine was recommended by WHO's Strategic Advisory Group of Experts (SAGE) for introduction in countries with high dengue burden and high transmission intensity to maximize public health impact. In addition to that, the vaccine has been included in the WHO's List of Prequalified Vaccines, underscoring its quality and reliability as an important dengue prevention method suitable for public programs. We are proud that our dengue vaccine is approved in over 40 countries worldwide and endorsed for the protection of communities and people against dengue, including those that have had dengue previously and those that have not.

What role do you see the dengue vaccine playing in Viet Nam's broader dengue prevention strategy, and how does it align with the government's current initiatives?

Dion Warren: The dengue vaccine is expected to have a significant impact on public health outcomes, especially in endemic countries like Viet Nam. The dengue vaccine can help protect people who have never had dengue before and people that have had dengue previously by reducing the number of new cases and reducing hospitalizations for severe disease. This impacts peoples' health and can result in significant economic benefits by alleviating the financial burden on healthcare systems and families, contributing to greater economic stability. The Ministry of Health in Viet Nam has taken proactive steps by implementing environmental cleanup efforts, vector control programs and public awareness campaigns. With the approval and availability of the dengue vaccine in Viet Nam, it adds an important option to the country's ongoing efforts to combat dengue.

The WHO's Dengue Vaccines Position Paper emphasized the prioritization and utilization of all available dengue prevention methods, including vaccination. We need to remember that in order to effectively prevent dengue and improve public health outcomes, an integrated dengue management strategy, covering vector control, case management, and community education, is needed alongside the introduction of dengue vaccination.

Based on its assessment, the WHO determined that the dengue vaccine will have the greatest public health impact in areas with a high dengue transmission, which includes countries like Viet Nam. Introduction of dengue vaccination should be accompanied by a well- designed communication strategy and community engagement. Individuals will still need to take additional steps to protect themselves and their loved ones from dengue, thereby improving the implementation of preventive measures, strengthening public health efforts, and reducing the impact of dengue on communities.

What is Takeda's long-term vision for dengue prevention in Viet Nam, and how do you see dengue vaccine evolving within this landscape?

Dion Warren: Takeda's ultimate goal is to improve public health and deliver a safe and effective dengue vaccine that can help address the significant global burden of dengue. This includes addressing the escalating dengue risks and cases in endemic countries like Viet Nam, a country listed as one of the most impacted from this disease by WHO. We have made important progress as we work to bring our dengue vaccine to people living in and travelling to endemic areas. To-date, Takeda's dengue vaccine has been approved in more than 40 countries, including European Union, Brazil, Argentina, Colombia, Indonesia, Thailand, Malaysia and here in Viet Nam.

In Viet Nam, Takeda continues to be committed to making our dengue vaccine accessible across the country. We aim to ensure that people in remote areas and high-risk groups, especially low-income families, can access the vaccine quickly and effectively. Acknowledging the burden dengue places on public health and the economy, expanding vaccination coverage is critical to our strategy against infectious diseases.

To achieve this, we will continue to strengthen partnerships with local health authorities, academic institutions, healthcare professionals and community organizations to ensure that dengue vaccine reaches those who need it most. We believe educational initiatives are critical to generate higher awareness about dengue and the importance of vaccination as well as other prevention methods.

Building the public awareness on dengue fever has been a priority of healthcare organizations around the world including Viet Nam and is seen as one of the critical elements in the integrated strategy by WHO toward Zero Dengue Death by 2030. How has Takeda contributed to this mission in Viet Nam?

Dion Warren: We have partnered with several medical associations and partners in Viet Nam to conduct education campaigns to help people understand the risks of dengue fever and encouraging the public to take proactive steps to protect themselves and their loved ones. In addition, our efforts also focus on scientific discussions and knowledge exchange on dengue prevention and safe immunization among the healthcare community.

In September, when Viet Nam started implementing dengue vaccine in public and private vaccination centers, we launched a public awareness campaign "Dengue Fever - The Surprising Truths" in partnership with Viet Nam Medical Association. The campaign effectively raised awareness about dengue fever and dispelled common misconceptions about the disease. Approaching this campaign with a strong understanding of the local environment, the team implemented a variety of creative methods to reach a broad audience. The campaign helped dispel myths and misconceptions that Vietnamese people often have about dengue fever and mosquitoes while clarifying that dengue can happen to anyone.

Within this campaign, Takeda has strengthened the educational materials by launching an information hub, sotxuathuyet.vn. This website serves as a central hub for reliable and up-to-date information on dengue fever, specifically tailored for the Vietnamese audience. It offers content in Vietnamese, covering topics such as: dengue symptoms and diagnosis, prevention tips and mosquito control methods, information about available vaccines and their importance & frequently asked questions (FAQs) to address common misconceptions about dengue.

By providing easy-to-understand and accessible information, the campaign empowers Vietnamese citizens to take charge of their health and protect themselves and their families from dengue fever with correct knowledge, while encouraging people to take preventive measures, such as using mosquito repellent and cleaning up their homes from stagnant water. This complements Takeda's initiatives by offering a long-term resource for continuous education and awareness.

As the battle against mosquitoes and dengue fever continues, Takeda remains steadfast in our mission to partner with health authorities and the public as well as private organizations. Our goal is to create a future where everyone is well-informed about dengue fever, able to outsmart mosquitoes and the dengue disease. We strive for a world where everyone is healthy and where this disease no longer casts a shadow over Viet Nam or other endemic countries.

Could you share your thoughts on the importance of partnerships and international collaboration in the fight against dengue as it has become a global public health threat?

Dion Warren: We strongly believe in the power of public-private collaborations and the synergy of combining global expertise with local insights to maximize impact. Dengue is a pressing global issue that demands a unified, cross-border approach.

By collaborating with local governments, NGOs, healthcare providers, and communities, we are committed to advancing integrated dengue prevention and management strategies. This approach not only addresses immediate challenges but also supports sustainable, long-term dengue prevention that will benefit communities for generations. 

We deeply appreciate the opportunity to contribute to these efforts and extend our gratitude to our partners for their unwavering dedication to combating this critical public health issue./.