People comforting their children suffering from dengue fever at a government hospital in Dhaka on … [+]
Dengue is a debilitating illness caused by infection with any of the four dengue viruses (dengue-1, -2, -3, and -4). Infections have risen significantly over the past two years, with a concerning lack of progress in the development of anti-dengue drugs and vaccines. This lack of advancement has left public health officials and clinicians worried about the limited options available to protect their populations and patients.
The Growing Dengue Crisis
The dengue viruses mainly circulate in tropical and subtropical regions, transmitted to humans by infected mosquitoes. Approximately 400 million infections occur each year, leading to about 100 million cases of illness. Many individuals recovering from dengue describe feeling extremely sick, with some fearing for their lives. Annual dengue-related deaths range from 8,000 to 40,000, with a significant number of fatalities occurring in children.
Upon initial infection with a specific dengue virus, the individual develops immunity against that strain, providing protection for several years. However, subsequent infections with a different dengue virus pose a higher risk of severe illness and death. Third or fourth infections typically result in milder symptoms due to immunity developed from previous exposures.
Since 2023, the global dengue crisis has worsened significantly. Dengue cases have surged worldwide, not only in endemic regions like Central and South America and Southeast Asia but also in new areas such as Nepal and Bangladesh. In 2022 alone, infections in the Caribbean and the Americas are more than 300% higher than the average of the past five years. Cases have also emerged in more temperate climates, with France reporting more locally acquired dengue infections in 2024 compared to previous years prior.
In 2023 and 2024, the U.S. saw a rise in dengue infections among travelers (4,730 cases) and locally acquired cases in states like Florida (249), Texas (2), and California (17). Puerto Rico, a frequent site of dengue outbreaks, reported 6,452 cases.
Challenges in Anti-Dengue Development
Simultaneously, as dengue infections escalate, developers of vaccines and drugs have halted their efforts in combating the disease. Sanofi, the maker of one of the two licensed dengue vaccines (Dengvaxia), recently announced the discontinuation of production, citing low global demand. The other licensed vaccine, TAK-003 by Takeda, has limitations in its efficacy against certain dengue virus strains.
Janssen, a subsidiary of Johnson & Johnson, has also ceased the development of a potential anti-viral drug for dengue, adding to the setbacks in combating the disease. These decisions have raised concerns about the future availability of effective treatments for dengue.
Can We Overcome the Dengue Challenge?
Despite the obstacles, some researchers continue to work on developing new anti-dengue vaccines and drugs. The ongoing efforts provide a glimmer of hope in the fight against the expanding dengue crisis.
There is growing interest in utilizing advanced antibody infusion technologies, similar to those used for treating COVID-19 patients, to prevent and treat dengue virus infections. Antibody preparations could offer temporary protection during outbreaks or serve as a treatment for individuals already infected.
The Serum Institute of India is currently conducting field tests on an antibody preparation specifically designed to treat patients with dengue virus. These antibodies aim to halt the virus’s replication in the body, thus reducing the severity of the illness experienced by patients. Academic groups and U.S. government agencies are also exploring the use of manufactured anti-dengue antibodies.
In terms of vaccines, the Instituto Butantan in Brazil has licensed dengue vaccine technology from the U.S. National Institutes of Health and has completed a large-scale field trial involving approximately 16,000 individuals to test their Butantan-DV vaccine formulation. The vaccine has shown good tolerance levels and has proven effective in preventing a significant number of dengue-1 and dengue-2 cases. The company has submitted all necessary documentation to Brazilian regulators (Anvisa) for the potential registration and availability of the vaccine in Brazil.
Panacea Biotech in India has also licensed materials from the NIH and initiated a large-scale vaccine field trial, set to conclude in 2024. Merck (MSD) is another licensee expected to conduct field trials. If successful, the vaccine’s availability in the U.S. may still be years away.
As for the future of dengue research, there is concern that the resources currently supporting these efforts may diminish. The U.S. government has historically been a key player in advancing dengue research through agencies like the Department of Defense, CDC, and NIH. However, depending on future leadership and funding decisions, there may be a risk of reduced support for infectious diseases research, impacting the progress of dengue prevention and treatment strategies.
It is crucial to maintain momentum in dengue research to address the increasing global health threat posed by the virus. Collaboration between government, industry, and academic sectors is vital to ensure the development of effective solutions to combat dengue infections.
