In this exclusive interview, BioPharma APAC engage with two distinguished experts in the field of infectious diseases and immunization: Prof. Tikki Pangestu, Co-Chair of the Asia Pacific Immunization Coalition (APIC) and Visiting Professor at the National University of Singapore, and Prof. Lulu Bravo, Paediatrician and Infectious Diseases Specialist, Professor Emeritus at the University of the Philippines Manila. Together, they shed light on the current dengue situation in Southeast Asia, factors contributing to dengue outbreaks, and comprehensive approaches to combat the rising public health threat. The interview covers topics ranging from integrated management strategies discussed at the 1st APIC Summit to the role of vaccines in dengue prevention, addressing vaccine hesitancy, and the impact of climate change on dengue transmission. The experts also share key takeaways and immediate recommendations for Southeast Asian countries to enhance their dengue management efforts. Join us in exploring the multifaceted aspects of dengue and the collaborative measures needed for a dengue-free future in the Asia-Pacific region.

• Tikki Pangestu, Co-Chair, Asia Pacific Immunization Coalition (APIC) and Visiting Professor, Yong Loo Lin School of Medicine, National University of Singapore

• Professor Lulu Bravo, Paediatrician and Infectious Diseases Specialist, Professor Emeritus of the College of Medicine, University of the Philippines Manila

• Can you provide an overview of the current dengue situation in Southeast Asia, and what are the key factors contributing to the increased risk of dengue outbreaks in the region?

Prof Lulu 

Despite measures such as vector control and personal protection: The WHO states that from 2015 to 2019, dengue cases in Southeast Asia increased by 46%. In our region, key factors contributing to dengue outbreaks include:

• Climate change: Warmer temperatures and higher humidity contribute to the growth of mosquito larvae and increases the rate at which the virus replicates in the mosquito as well as the survival rate of mosquitoes. 

• Urbanization: Unplanned urbanization, which often comes with increase in construction sites, poor sanitation, unstable water supply and limited waste management programmes, can result in increased breeding grounds for mosquitos, especially when open water containers are used to ensure water supply. 

• Lack of effective prevention strategies: Vector control is just one component to prevent dengue and can have limitations in certain settings. Insecticide, though effective, could lead to resistance in mosquitoes after prolonged use. A Malaysian study showed that 75% of the Aedes aegypti mosquito population were resistant to one type of insecticide, while in Vietnam, the mosquito population proved resistant to five types of insecticides. Many countries also do not have sufficient dengue surveillance, meaning that epidemics can be well underway before they are recognized, resulting in overburdening of healthcare systems. 

• The recent 1st APIC Summit on Infectious Diseases and Immunisation discussed the benefits of integrated approaches to dengue management. Could you elaborate on what these integrated approaches entail and how they can effectively address the rising public health threat of dengue in the Asia-Pacific?

Prof Tikki 

A holistic perspective is needed to address dengue effectively. This includes vector management, communication, education and awareness, clinical management and vaccination. Most, Southeast Asian countries already have dengue management measures in place, such as disposal of all containers capable of holding water, spraying insecticide indoors, and fuming. Some countries have also successfully deployed the Wolbachia Method, which involves releasing mosquitos carrying the Wolbachia bacterium, into high-risk areas. Wolbachia bacteria in Aedes aegypti mosquitos reduce the risk of dengue transmission, as the bacteria make it more difficult for the dengue virus to replicate. In addition, the WHO also recommends personal protection measures such as wearing long sleeves and using mosquito repellent.

However, these measures are only partly effective – we need a holistic approach that starts with better surveillance of dengue areas to support potential strategies on the communication of the benefits of dengue vaccination. We should not underestimate the role of vaccination in dengue management. 

• What are some best practices in dengue management that have proven to be effective and can be adopted across Southeast Asian countries to combat this disease more efficiently?

Prof Lulu 

Most Southeast Asian countries employ similar dengue management measures. In the Philippines, for example, the Metropolitan Manila Development Authority recommends the public to cover and clean water containers, wear protective clothing, drain and clean roof gutters, apply mosquito repllent, etc. 

In Indonesia, the Ministry of Health recommends similar measures like covering and cleaning water storages, recycling unused items and wearing more clothing to minimize risk of exposure to mosquitos. In Vietnam, prevention efforts include community education campaigns, that aim to reduce mosquito breeding sites, and spraying insecticide. Proper waste management in the streets is also encouraged to eliminate mosquito breed sites.

Simple measures like education and disease awareness are very effective to ensure success in holistic dengue management. Educating around symptoms allows family members and doctors to quickly identify dengue symptoms and refer patients to hospitals for treatment. This also leads to increased surveillance in the community, as an Indonesian project has successfully shown. In addition, raising awareness of the risk factors of dengue can help to sensitize the community and enable them to support dengue prevention.

• The World Health Organization (WHO) recently issued recommendations regarding dengue vaccination. Can you provide insights into these recommendations and their potential impact on dengue management in the region?

Prof Tikki 

In October, the World Health Organization’s (WHO) Strategic Advisory Group of Experts (SAGE) on Immunization recommended that vaccination should be considered for introduction in settings with high dengue disease burden and high transmission intensity to maximize the public health impact and minimize any potential risk in persons who had previously not had dengue. SAGE also recommended that an introduction of the dengue vaccine should be accompanied by a well-designed communication strategy and engage the community. 

This is an important signal for the region, as it underscores that vaccines are an important part of managing dengue in a holistic way to achieve zero-mortality by 2030. 

In Asia, the APIC Summit on Infectious Diseases & Immunization highlighted the key intersections between science, policy and effective communications to overcome vaccine hesitancy. Vaccine development has benefitted, and will continue to benefit, from unprecedented advances in the science of vaccinology and the key role of partnerships between the public sector, industry and academia. 

But at the end of the day, it is still ‘vaccination and not vaccines which saves lives’. The impact of new vaccines in the future, including much improved versions of vaccines to combat dengue globally, is closely dependent on the development of effective and sustainable public policies and strategies or implementation of these vaccines. The success of these policies will also depend on vaccine acceptance among the people. This entails overcoming fear and uncertainty surrounding ‘vaccine hesitancy’ in the age of misinformation and conspiracy theories. People’s confidence and acceptance of the overall value and benefits of vaccination underpins the ultimate success of these new vaccines as an important public health tool to reduce dengue prevalence, morbidity and mortality at the global level.

For instance, the introduction of new dengue vaccine in Indonesia and Thailand has increased discussions of dengue prevention. While the uptake of the vaccine is picking up pace, with ongoing education campaigns, we are one step closer to zero dengue deaths by 2030. 

• Could you discuss the role of vaccines in effective dengue management and whether vaccine hesitancy is a significant roadblock to achieving dengue-zero plans and programs in many countries?

Prof Tikki 

Vaccines are essential to the sustainable management of dengue. With the ongoing surge of dengue cases despite preventative measures, such as fuming, covering water containers or using mosquito repellent, it is important to take a holistic approach:

• Education: Public education programmes will not only raise awareness about causes and symptoms of dengue, as well as precautionary measures, but also sensitize the population and increase surveillance.
• Sustainable healthcare system and improved surveillance: it is essential to map out where dengue cases occur most to implement preventative measures and ensure that hospitals can handle influx of patients during an outbreak.
• Vaccination: Common preventative measures are often not sustainable, launched too late, or simply because it is virtually impossible to eradicate every mosquito breeding site. To reach zero mortality, vaccination is a key to control infections. Very often, children and the elderly are the most impacted, with more children suffering from severe cases of dengue requiring intensive care. 

However, vaccination must be complemented with thought-through, transparent communication strategies to address and alleviate any public concerns. Trust can only be achieved through education, culturally appropriate content, and stakeholder collaboration. 

• In the context of climate change, how are changing environmental conditions affecting the transmission and prevalence of dengue, and what strategies can be employed to mitigate these effects?

Prof Lulu 

Higher temperatures, increased precipitation and frequent flooding has provided an ideal breeding environment for the Aedes aegypti mosquito, the main carrier of dengue. Such changes not only increased the speed of multiplying of the Aedes aegypti mosquito, but also enables the virus to replicate faster,. As a result, if no measures are implemented dengue will impact 60 percent of the world’s population by 2080. 

While there is no treatment against the dengue virus itself, many common prevention methods have been adopted to reduce the risk of dengue transmission. In the Philippines, the National Dengue Prevention and Control Program has been in place since 1993 to manage vector management, outbreak response and case diagnosis, and health promotion. Wearing long pants and long-sleeved shirts, using mosquito repellent, empty water containers and dispose of any containers that can hold water are some of the most common methods for the public to prevent dengue,.

While all preventative measures are essential, they do have limitations. Recent research has revealed that mosquitoes in several Asian countries have undergone mutations that makes them impervious to chemicals commonly used to eradicate them. Other challenges in the region include the eradication of breeding sites in areas with unreliable water supply, as residents rely on open water containers to store water. It is therefore crucial to adopt a holistic approach to that includes tailored communication strategies, vector management, and vaccination. Recently in the Philippines, many doctors, including paediatricians, have emphasized on the role of vaccines alongside other dengue management measures such as vector control and diagnosis, to achieve zero mortality by 2030. 

• Lastly, what are the key takeaways from the 1st APIC Summit on Infectious Diseases and Immunisation, and what are the immediate actions and recommendations that Southeast Asian countries should consider to enhance their dengue management efforts?

Prof Lulu 

While effective dengue management requires vector control, surveillance, education and vaccination, collaboration is essential to address the threat of dengue. The healthcare ecosystem, comprising of public and private sectors, media and the public should collaborate on disease prevention and management together. In the Philippines, the nationwide Dengue Prevention and Control Program covers surveillance, case management, diagnosis, integrated vector management, outbreak response, health promotion, advocacy, and research. In Thailand, the ING-MA campaign, which uses a virtual avatar to tell the dengue victim story,  gained much public attention and increased awareness towards dengue prevention. With integrated initiatives, we are confident that we could reach zero mortality by 2030.

Prof Tikki 

While collaboration is important, we should also focus on education, via proactive public communication. To complement vaccine innovation, communication on the benefits of dengue vaccines is crucial to dispel vaccine hesitancy, misconceptions, and fears. Lessons can be learned from the COVID-19 pandemic and applied to the introduction of the dengue vaccine. Evidence-based educational content is key to promote trust. 

To address the threat of dengue in Indonesia, campaigns like KOBAR Lawan Dengue, National Vector Ayo3MPlus Vaksin DBD and Langkah Bersama Cegah DBD programme were launched to educate the public about the dangers of dengue and the importance of prevention, including via vaccines. In Malaysia, the Dengue Prevention Advocacy Malaysia initiated active involvement from the government, civil society, academia, private sector, media, and the community to mobilise ‘whole-of-society’ action against dengue. We are confident that zero dengue mortality by 2030 is possible through joint efforts across vector control, surveillance, education and vaccination.

Ref-

_____

WHO, Dengue in Southeast Asia, https://www.who.int/southeastasia/health-topics/dengue-and-severe-dengue, Accessed November 2023

[1] Glassman, R., Scarpino, S., Gilmour, J., The Increasing Burden of Dengue Fever in a Changing Climate, The Rockefeller Foundation, https://www.rockefellerfoundation.org/blog/the-increasing-burden-of-dengue-fever-in-a-changing-climate/, Accessed November 2023

[1] Barnagarwala, T., Special report: Why is India seeing a massive dengue outbreak this year? https://scroll.in/article/1011940/special-report-why-is-india-seeing-a-massive-dengue-outbreak-this-year, December 2021, Accessed November 2023

[1] Barnagarwala, T., Special report: Why is India seeing a massive dengue outbreak this year? https://scroll.in/article/1011940/special-report-why-is-india-seeing-a-massive-dengue-outbreak-this-year, December 2021. Accessed: November 2023.

[1] Lubin, M.D., Dengue Fever in Asia and Southeast Asia. Available from: https://ballardbrief.byu.edu/issue-briefs/dengue-fever-in-south-and-southeast-asia, Winter 2023. Accessed: November 2023.

[1] Lubin, M.D., Dengue Fever in Asia and Southeast Asia. Available from: https://ballardbrief.byu.edu/issue-briefs/dengue-fever-in-south-and-southeast-asia, Winter 2023. Accessed: November 2023.

[1] World Mosquito Program, How it Works. Available from: https://www.worldmosquitoprogram.org/en/work/wolbachia-method/how-it-works. Accessed: November 2023.

[1] Metropolitan Manila Development Authority, Dengue Prevention Guide. Available from: https://mmda.gov.ph/faq/20-faq/5479-dengue-prevention-guide-faq-updated-june-7-2022.html. Accessed: November 2023.

[1] Makrufardi F, Phillabertha PS, Safika EL, Sungkono. Factors associated with dengue prevention behaviour in riverbank area: A cross-sectional study. Ann Med Surg (Lond). 2021 Jun 2;66:102450. doi: 10.1016/j.amsu.2021.102450. PMID: 34141421; PMCID: PMC8187934, https://pubmed.ncbi.nlm.nih.gov/34141421/. Accessed: November 2023.

[1] IFRC, Dengue in Indonesia – How community trust enabled early detection and response to a dengue case in Indonesia. Available from: https://www.ifrc.org/sites/default/files/2022-10/Dengue-Indonesia-Prevent-Epidemics.pdf, December 2021. Accessed: November 2023.

[1] Clarke, Chris and Trivisonno, Angie, How a digital tool aims to prevent Vietnam's Dengue epidemic, The University of Queensland. Available from: https://stories.uq.edu.au/research/2023/e-dengue-aims-to-prevent-vietnam-dengue-epidemic/index.html#:~:text=To%20date%2C%20dengue%20prevention%20efforts,areas%20with%20reported%20dengue%20cases. Accessed: November 2023.

[1] Lubin, M.D., Dengue Fever in Asia and Southeast Asia, https://ballardbrief.byu.edu/issue-briefs/dengue-fever-in-south-and-southeast-asia, Winter 2023, Accessed November 2023

[1] IFRC, Dengue in Indonesia – How community trust enabled early detection and response to a dengue case in Indonesia, https://www.ifrc.org/sites/default/files/2022-10/Dengue-Indonesia-Prevent-Epidemics.pdf, December 2021, Accessed November 2023

[1] WHO, WHO recommends R21/Matrix-M vaccine for malaria prevention in updated advice on immunization, https://www.who.int/news/item/02-10-2023-who-recommends-r21-matrix-m-vaccine-for-malaria-prevention-in-updated-advice-on-immunization, October 2023, Accessed November 2023

[1] Takeda, Takeda’s Dengue Vaccine Recommended by World Health Organization Advisory Group for Introduction in High Dengue Burden and Transmission Areas in Children Ages Six to 16 Years, https://www.takeda.com/newsroom/newsreleases/2023/Takeda-Dengue-Vaccine-Recommended-by-World-Health-Organization-Advisory-Group-for-Introduction-in-High-Dengue-Burden-and-Transmission-Areas-in-Children-Ages-Six-to-16-Years/, October 2023, Accessed November 2023

[1] World Mosquito Program, Dengue’s deadly impact on children, https://www.worldmosquitoprogram.org/en/news-stories/stories/explainer-dengues-deadly-impact-children#:~:text=Anyone%20can%20experience%20the%20more,risk%20of%20severe%20dengue%20illness, Accessed November 2023

[1] Reuters, WHO warns of dengue risk as global warming pushes cases near historic highs, https://www.reuters.com/business/healthcare-pharmaceuticals/who-warns-dengue-risk-global-warming-pushes-cases-near-historic-highs-2023-07-21/, July 21, 2023, Accessed November 2023

[1] Glassman, R., Scarpino, S., Gilmour, J., The Increasing Burden of Dengue Fever in a Changing Climate, The Rockefeller Foundation, https://www.rockefellerfoundation.org/blog/the-increasing-burden-of-dengue-fever-in-a-changing-climate/, Accessed November 2023

[1] Glassman, R., Scarpino, S., Gilmour, J., The Increasing Burden of Dengue Fever in a Changing Climate, The Rockefeller Foundation, https://www.rockefellerfoundation.org/blog/the-increasing-burden-of-dengue-fever-in-a-changing-climate/, Accessed November 2023

[1] Ong EP, Obeles AJT, Ong BAG, Tantengco OAG. Perspectives and lessons from the Philippines' decades-long battle with dengue. Lancet Reg Health West Pac. 2022 Jun 24;24:100505. doi: 10.1016/j.lanwpc.2022.100505.

[1] Philippine Red Cross, Philippine Red Cross warns public of dengue fever risk, https://redcross.org.ph/2022/06/16/philippine-red-cross-warns-public-of-dengue-fever-risk/, June 16, 2022, Accessed October 2023

[1] Ong EP, Obeles AJT, Ong BAG, Tantengco OAG. Perspectives and lessons from the Philippines' decades-long battle with dengue. Lancet Reg Health West Pac. 2022 Jun 24;24:100505. doi: 10.1016/j.lanwpc.2022.100505. PMID: 35789734; PMCID: PMC9249805, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9249805/#:~:text=To%20address%20this%20growing%20problem,and%20Control%20Program%20in%201993.&text=The%20program%20consists%20of%20case,promotion%20and%20advocacy%2C%20and%20research, Accessed November 2023

[1] CNA News, Bangladesh dengue deaths top 1,000 in worst outbreak on record, https://www.channelnewsasia.com/asia/bangladesh-dengue-deaths-worst-outbreak-record-mosquitoes-climate-change-3814286, October 2, 2023. Accessed: October 2023.

[1] Ong EP, Obeles AJT, Ong BAG, Tantengco OAG. Perspectives and lessons from the Philippines' decades-long battle with dengue. Lancet Reg Health West Pac. 2022 Jun 24;24:100505. doi: 10.1016/j.lanwpc.2022.100505. PMID: 35789734; PMCID: PMC9249805, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9249805/#:~:text=To%20address%20this%20growing%20problem,and%20Control%20Program%20in%201993.&text=The%20program%20consists%20of%20case,promotion%20and%20advocacy%2C%20and%20research. Accessed: November 2023.

[1] Inquirer.net, FDA: 3 new dengue vaccines in pipeline, https://newsinfo.inquirer.net/1800953/fda-3-new-dengue-vaccines-in-pipeline, July 13, 2023. Accessed: November 2023.

[1] Inquirer.net, FDA: 3 new dengue vaccines in pipeline, https://newsinfo.inquirer.net/1800953/fda-3-new-dengue-vaccines-in-pipeline, July 13, 2023. Accessed: November 2023.

[1] Malaysian Business Online, Dengue Prevention Advocacy Malaysia Unifying and Synergising Forces in the Battle Against Dengue, 23 June 2023. Available at: https://www.malaysian-business.com/index.php/wordpress/item/8246-dengue-prevention-advocacy-malaysia-unifying-and-synergising-forces-in-the-battle-against-dengue. Accessed: November