Q What is the context ?
A A Pune-based bio-pharma company is currently is likely to develop India’s first mRNA COVID-19 vaccine.
Q What is Ribo Nucleic Acid (RNA) ?
A
- RNA is an important biological macromolecule that is present in all biological cells.
- It is principally involved in the synthesis of proteins, carrying the messenger instructions from DNA, which itself contains the genetic instructions required for the development and maintenance of life.
- In some viruses, RNA, rather than DNA, carries genetic information.
- The type of RNA dictates the function that this molecule will have within the cell.
- Aside from the coding region of messenger RNA (mRNA) molecules that will be translated into proteins, other cellular RNA elements are involved in different processes.
Q What is mRNA?
A
- Messenger RNA (mRNA) is a single-stranded RNA (Ribo Nucleic Acid) molecule that is complementary to one of the DNA strands of a gene.
- The mRNA is an RNA version of the gene that leaves the cell nucleus and moves to the cytoplasm where proteins are made.
- During protein synthesis, an organelle called a ribosome moves along the mRNA, reads its base sequence, and uses the genetic code to translate each three-base triplet, or codon, into its corresponding amino acid.
Q What are mRNA vaccines?
A
- Such vaccines make use of the messenger RNA molecules that tell the body’s cells what proteins to build.
- The mRNA, in this case, is coded to tell the cells to recreate the spike protein of the coronavirus SARS-CoV-2, which causes Covid-19.
- It is the spike protein — which appears as spikes on the surface of the coronavirus — that initiates the process of infection; it allows the virus to penetrate cells, after which it goes on to replicate.
- A coronavirus vaccine based on mRNA, once injected into the body, will instruct the body’s cells to create copies of the spike protein.
- In turn, this is expected to prompt the immune cells to create antibodies to fight it.
- These antibodies will remain in the blood and fight the real virus if and when it infects the human body.
Q What are other types of vaccine?
A (1) Vector vaccine:
- In this type of vaccine, genetic material from the COVID-19 virus is placed in a modified version of a different virus (viral vector).
- When the viral vector gets into your cells, it delivers genetic material from the COVID-19 virus that gives your cells instructions to make copies of the S protein.
- Once your cells display the S proteins on their surfaces, your immune system responds by creating antibodies and defensive white blood cells.
- If you later become infected with the COVID-19 virus, the antibodies will fight the virus.
(2) Protein subunit vaccine:
- Subunit vaccines include only the parts of a virus that best stimulate your immune system.
- This type of COVID-19 vaccine contains harmless S proteins.
- Once your immune system recognizes the S proteins, it creates antibodies and defensive white blood cells.
- If you later become infected with the COVID-19 virus, the antibodies will fight the virus.
