GS Paper 3
Syllabus: Science and Technology
Source: Nobelprize
Context: The 2023 Nobel Prize in Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for their research enabling the development of mRNA vaccines against COVID-19.
What are RNAs, types of RNAs, and differences with DNAs: See the infographic
What is mRNA?
mRNA stands for “messenger RNA.” It is a molecule that carries genetic information from DNA to the ribosomes in cells, where it is used as a template for protein synthesis.
What are mRNA vaccines?
mRNA vaccines are a type of vaccine that uses messenger RNA (mRNA) to instruct cells in the body to produce a specific viral protein, such as the spike protein of a COVID-19 virus. This protein triggers an immune response, helping the body build immunity against the virus.
Notably, mRNA vaccines do not contain live or weakened viruses, making them safe and effective tools for preventing infectious diseases like COVID-19.
How are these vaccines different (mRNA vs. DNA)?
Comparison of mRNA and DNA vaccines:
| Aspect | mRNA Vaccines | DNA Vaccines |
| Genetic Material | Use messenger RNA (mRNA) as genetic material. | Use DNA (deoxyribonucleic acid) as genetic material. |
| Stability | mRNA is relatively fragile and needs lipid protection to remain stable. | DNA is more stable and does not require lipid protection |
| Delivery | mRNA vaccines deliver instructions directly to the cell to produce viral proteins. | DNA vaccines often use a harmless virus (vector) to deliver DNA instructions to cells. |
| Storage | mRNA vaccines require ultra-low temperatures (e.g., -90°C to -50°C) for storage and transportation. | DNA vaccines can typically be stored at less extreme temperatures (so more suited for tropical countries like India) |
| Flexibility | Both mRNA and DNA vaccines can be adapted quickly to address emerging variants and new diseases by changing the genetic code. | DNA vaccines offer flexibility but may require additional development steps for adaptation. |
| Examples | Pfizer/BioNTech and Moderna COVID-19 vaccines are mRNA-based | E.g., Zydus Cadila’s ZyCoV-D vaccine; Covishield (by Serum and Oxford) use DNA wrapped in another virus, which then instructs cells to make the spike protein. |
Contributions of Katalin Karikó and Drew Weissman:
Katalin Karikó and Drew Weissman made important contributions to the development of COVID-19 mRNA vaccines (Pfizer and Moderna’s vaccine).
Previous to Katalin and Weissman’s findings, lab-grown genetically engineered mRNA was recognized as foreign by the body’s dendritic cells (Nerve Cells), leading to unwanted inflammatory reactions.
Kariko and Weissman realized that RNA from mammalian cells is often chemically modified, whereas lab-created mRNA lacks these modifications. They hypothesized that modifying the bases in lab-created mRNA could reduce the inflammatory response. Their experiments confirmed this hypothesis, with base modifications significantly reducing inflammation when introduced to dendritic cells.
These discoveries, first published in 2005 and further developed in 2008 and 2010, laid the foundation for mRNA vaccine technology
Future significance: Their work not only revolutionized vaccine technology but also has the potential for broader applications in treating diseases and delivering therapeutic proteins.
About the Duo:
Katalin Kariko, from Hungary, and Drew Weissman, from the USA, have extensive backgrounds in biochemistry and medicine, and their collaborative efforts have revolutionized vaccine development, saving countless lives during the COVID-19 crisis.
Insta Links:
Prelims Links:
In the context of vaccines manufactured to prevent COVID-19 pandemic, consider the following statements: (UPSC 2022)
- The Serum Institute of India produced COVID-19 vaccine named Covishield using mRNA platform.
- Sputnik V vaccine is manufactured using vector based platform.
- COVAXIN is an inactivated pathogen based vaccine.
Which of the statements given above are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Widespread resistance of malarial parasite to drugs like chloroquine has prompted attempts to develop a malarial vaccine to combat malaria. Why is it difficult to develop an effective malaria vaccine? (UPSC 2010)
(a) Malaria is caused by several species of Plasmodium
(b) Man does not develop immunity to malaria during natural infection
(c) Vaccines can be developed only against bacteria
(d) Man is only an intermediate host and not the definitive host
Ans: (b)
With reference to recent developments regarding ‘Recombinant Vector Vaccines’, consider the following statements
- Genetic engineering is applied in the development of these vaccines.
- Bacteria and viruses are used as vectors.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Ans: (c)
