India's First Dengue Vaccine: Phase 3 Trials Approach Finish Line, Promising Hope Against Deadly Virus

Dengue fever, a viral infection transmitted by the Aedes aegypti mosquito, poses a significant health challenge, particularly in India, which accounts for a substantial portion of the 100–400 million global infections. As the monsoon season approaches, bringing with it a surge in cases, there is renewed hope. The nation's first dengue vaccine is nearing the end of its testing phase, with Phase 3 trial enrollment almost finalized.

The Danger of Dengue Fever

Dengue fever, spread by Aedes mosquitoes, is characterized by high fever, intense headaches, joint and muscle pain, and a potentially dangerous drop in blood platelet count. In severe instances, the disease can progress to bleeding, organ failure, and even death. Children and the elderly are particularly vulnerable.

Hurdles in Vaccine Development

Developing a safe and effective dengue vaccine has been a long-standing challenge for scientists. The complexity arises from the existence of four distinct dengue virus types. An effective vaccine must provide protection against all four serotypes. While some vaccines developed in other countries have shown promise, they have not achieved widespread use.

India's Indigenous Vaccine: TetraVax-DV

The Serum Institute of India (SII) is at the forefront of developing India’s first dengue vaccine, named TetraVax-DV. This vaccine is engineered to protect against all four dengue virus types. Similar to other vaccines, it employs a weakened form of the virus to stimulate the body's immune system to combat dengue. Since TetraVax-DV does not contain a live virus, it cannot cause the disease itself.

Key Attributes of TetraVax-DV

• Targets all four dengue virus types
• Developed using advanced technology
• Undergoing rigorous testing for safety and efficacy

Understanding Phase 3 Trials

Before any vaccine can be approved for public use, it must undergo several phases of testing:

• Phase 1: A small group of healthy volunteers are given the vaccine to assess its safety.
• Phase 2: A larger group receives the vaccine to evaluate the immune response and identify potential side effects.
• Phase 3: Thousands of volunteers are enrolled to determine the vaccine's effectiveness in a larger population.

Phase 3 is critical because it demonstrates whether the vaccine can effectively prevent dengue within a community.

Current Status in India

The Phase 3 trial for India’s dengue vaccine commenced in 2023. The trial is being conducted at over 20 locations nationwide, encompassing both urban and rural settings. The goal is to enroll more than 10,000 volunteers, including children and adults from diverse backgrounds. Enrollment is nearing completion, and preliminary results are encouraging.

What's Next?

• Monitoring: Volunteers will be closely monitored for any side effects and to assess their protection against dengue.
• Data Analysis: Scientists will analyze the data to determine the vaccine's overall efficacy.
• Approval: If the results are favorable, Indian health authorities could approve the vaccine within the next year.

Significance of the Vaccine

India faces a high burden of dengue cases, placing a strain on hospitals and causing distress for families. A safe and effective vaccine has the potential to:

• Reduce the number of dengue cases
• Decrease hospital admissions
• Save lives, particularly among children
• Alleviate the economic burden on families and the healthcare system

While the dengue vaccine holds immense promise, preventative measures remain crucial. These include protecting oneself from mosquito bites through the use of repellents and appropriate clothing, eliminating mosquito breeding grounds by covering drains, and preventing the accumulation of stagnant water.

Source

The Indian Council of Medical Research (ICMR) and Panacea Biotec