New Delhi: Pune-based Serum Institute of India (SII) has joined hands with an international medical research organisation to accelerate the clinical development of an affordable monoclonal antibody for dengue, a vector-borne disease that has emerged as a major public health challenge for countries like India.
The SII and the Drugs for Neglected Diseases initiative (DNDi) entered into a partnership on 13 June, declaring they will develop a workplan to carry out late stage trials and access activities, along with a joint strategy to raise necessary funds and resources for developing the potential drug candidate, formerly known as VIS513 or Dengueshield.
Additionally, a joint project team will be formed to advance clinical trials, with the goal of registering and deploying the dengue monoclonal antibody in India and other dengue-endemic countries, provided the studies confirm its safety and efficacy, they said in a joint statement.
Dengue is a climate-sensitive, viral infection transmitted to humans through the bite of infected mosquitoes, mainly aedes aegypti that also spreads pathogens which cause zika and chikungunya fever.
While many dengue infections are asymptomatic or produce only mild illness, the virus can in several patients cause more severe disease, and even death. It is estimated that one in 20 people who get sick with dengue get severely ill.
Despite the alarmingly rising prevalence and severity of the vector-born disease, there is still no specific treatment available for dengue.
The collaboration aims at accelerating the development of an effective and affordable monoclonal antibody treatment for dengue caused by any of the four serotypes of dengue virus, in close cooperation with endemic countries, including Thailand, Malaysia, and Brazil. Despite the… pic.twitter.com/8el96cL9Yo
— SerumInstituteIndia (@SerumInstIndia) June 13, 2025
The latest collaboration
The VIS513 is developed by US-based biotechnology company Visterra, a biologic research early-stage clinical development arm of Tokyo-based Otsuka Pharmaceuticals. The VIS513 was later licensed to the SII.
The SII has carried out phase 1 and phase 2 trials of the therapy in India, proving its safety and efficacy in a small number of humans. Currently, the pivotal Phase III clinical trial is underway in India, and the collaboration paves way for the expansion of the drug candidate in several other countries where dengue is endemic, the two entities said.
Dengue poses a significant threat, with 3.9 billion people at risk and cases more than doubling each year since 2021. The World Health Organization says the actual number of dengue cases globally rose from 5,05,430 cases in 2000 to 5.2 million in 2019.
India is among the top 30 countries with the highest burden of dengue, and according to government estimates, among the 20-25 percent of cases where dengue symptoms are clinically apparent, children are at a significantly higher risk of hospitalisation and mortality.
This year, the country registered 12,043 dengue cases and six deaths till March, according to the National Centre for Vector Borne Disease Control statistics. Last year, 2,33,519 cases and 297 deaths were reported but experts underline the actual burden of the disease is much higher.
“India reports tens of thousands of dengue cases every year, with outbreaks occurring every two to three years in different states,” said Dr Kavita Singh, the Asia Continental Lead & Director South Asia, DNDi.
What is deeply concerning is that dengue is no longer confined to historically endemic regions but is rapidly expanding into newer states, she added.
“Addressing this growing threat demands a multi-pronged approach, including strengthened vector control, surveillance, community awareness and, critically, the development of effective treatments and diagnostics,” Singh also said.
A 2024 dengue bulletin by the WHO said that the highest number of dengue cases was recorded in 2023, affecting over 80 countries in all regions of the WHO.
In 2023, a combination of ongoing dengue transmission and a significant surge in cases led to a record-breaking 6.5 million infections and over 7,300 deaths globally.
New monoclonal antibody offers help
Monoclonal antibodies, sometimes also called passive immunisation, are special types of proteins called antibodies which are made in laboratories. Dengue is caused by any of four dengue virus (DENV) serotypes (DENV 1 to 4), each of which can cause minor dengue fever or severe dengue.
Dengue can be anything from an infection without symptoms, a mild fever or a severe fever with musculoskeletal pain to haemorrhagic fever (low platelets leading to bleeding) and dengue shock syndrome (severe form of dengue infection that can lead to circulatory collapse).
The latter two can be very severe and result in death if not recognised and treated early. And these two conditions usually happen, not in the first but in subsequent infection, when the dengue virus strain is different from the one that caused the earlier infection.
According to Dr R.R. Dutta, the head of internal medicine with Paras Health in Gurugram, medical practitioners need to develop customised treatment plans which focus on avoiding severe disease outcomes such as dengue hemorrhagic fever and shock syndrome in patients who experience severe symptoms.
Dr Manisha Arora, director, internal medicine with C K Birla Hospital in Delhi, pointed out that unlike bacterial infections, where antibiotics can attack the root cause and cure the disease, dengue, being a viral infection, lacks such a targeted treatment.
If we had a specific antiviral for dengue, it would help in directly attacking the virus, thereby reducing the risk of complications and improving patient outcomes, said the clinician.
“Unfortunately, in the absence of such antivirals, doctors are limited to providing only supportive care, such as fluid management, monitoring vital signs, and treating complications as they arise,” Arora stressed.
The current treatment regime for severe dengue patients depends heavily on early detection and timely intervention, but it doesn’t address the underlying virus.
“The lack of specific antivirals limits our ability to prevent disease progression, especially in severe cases. If an effective antiviral existed, it could potentially reduce hospitalisations, lower the risk of long-term health issues and ultimately save more lives,” Arora also said.
The monoclonal antibody candidate by the SII, as per available information, has shown efficacy against all dengue virus serotypes with no serious adverse events.
The therapy candidate, designed to be effective against all four DENV serotypes, works by binding to a specific part of DENV called the envelope protein domain III, known for its role in viral entry into host cells and its immunogenicity.
The results from a phase 1 clinical trial of the drug involving 40 participants in India—based on follow-ups lasting 85 days—whihc was published in the Lancet last year, showed the drug was found effective and safe in early testing.
AV-1, another investigational human monoclonal antibody developed by US-based company AbViro, is also in a similar stage of development and is undergoing safety and efficacy trials across various countries.
A dengue vaccine by Japanese pharma giant Takeda, approved by some other countries, is also undergoing trials in India to generate local safety and efficacy data ahead of its regulatory approval in the country.
(Edited by Ajeet Tiwari)
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