India’s National Centre for Biological Sciences (NCBS), Bengaluru, has developed the country’s first and only DNA vaccine for dengue. The vaccine has shown promising results and has been in development since 2019.

DNA Vaccine versus RNA Vaccine

A DNA vaccine uses a copy of a genetic sequence from a part of a pathogen, such as a virus or bacteria, to stimulate the body’s immune system. Specifically, it is known as a “plasmid DNA vaccine.” In contrast, an RNA vaccine uses a copy of a natural chemical called messenger RNA (mRNA) to produce an immune response in humans. The delivery of mRNA is achieved through lipid nanoparticles.

The world’s first DNA vaccine, ZyCoV-D, was approved in 2021 for emergency use against COVID-19. DNA vaccines have several benefits over RNA vaccines. For example, they are more stable and can be manufactured rapidly and at scale, with lower cold chain requirements.

Benefits of DNA Vaccines

Stability and Safety

One of the primary advantages of DNA vaccines is their stability and safety. DNA vaccines are non-infectious, and they carry no potential toxicity from viral vectors. Additionally, they do not pose a risk of integration into the host cell genome, which is a potential concern with RNA vaccines.

Efficacy and Boosting

DNA vaccines also stimulate both the humoral and cellular arms of the adaptive immune system, making them highly effective. They pose minimal risk of anti-vector immunity, which is when the immune system develops a response to the viral vector used to deliver the vaccine.

Rapid and Scalable Manufacturing

Furthermore, DNA vaccines can be manufactured rapidly and at scale, with lower cold chain requirements. This makes them ideal for use in resource-limited settings.

Challenges of DNA Vaccines

Although DNA vaccines have several advantages, there are also some challenges associated with their use. For example, there is relatively limited data on their safety and efficacy in humans. Additionally, there is a risk of the development of anti-nuclear antibodies, and there is a concern that the widespread use of DNA vaccines could lead to the induction of antibiotic resistance.

MCQs on India’s First DNA Vaccine for Dengue

  1. What is the primary advantage of DNA vaccines over RNA vaccines?
    A. Higher efficacy
    B. Lower cold chain requirements
    C. Stability and safety
    D. Minimal risk of anti-vector immunity
    Correct Answer: C. Stability and safety
    Explanation: DNA vaccines are non-infectious and carry no potential toxicity from viral vectors, making them safer than RNA vaccines. They also do not pose a risk of integration into the host cell genome, which is a potential concern with RNA vaccines. Additionally, DNA vaccines are stable and can be manufactured rapidly and at scale, with lower cold chain requirements.
  2. What is the risk associated with the development of anti-nuclear antibodies from DNA vaccines?
    A. Antibiotic resistance
    B. Potential toxicity
    C. Reduced efficacy
    D. None of the above
    Correct Answer: D. None of the above
    Explanation: The development of anti-nuclear antibodies is a potential risk associated with DNA vaccines. These antibodies target the DNA in a person’s cells, which could potentially cause autoimmune disorders. However, this does not lead to antibiotic resistance.
  3. What is the primary advantage of DNA vaccines for use in resource-limited settings?
    A. Higher efficacy
    B. Lower cold chain requirements
    C. Stability and safety
    D. Rapid and scalable manufacturing
    Correct Answer: D. Rapid and scalable manufacturing
    Explanation: DNA vaccines can be manufactured rapidly and at scale, with lower cold chain requirements, making them ideal for use in resource-limited settings. This is due to their stability and the fact that they are non-infectious, which means that they can be manufactured safely and easily.

Loading