Corbevax and Covovax
2021 DEC 31
Science and Technology > Miscellaneous > COVID 19
Why in news?
- India gave emergency-use authorisation to two more vaccines- Corbevax and Covovax.
- Corbevax was developed by Hyderabad-based biopharmaceutical firm Biological E., the Baylor College of Medicine in the US, and US-based company Dynavax Technologies.
- Corbevax is what is known as a protein subunit vaccine. It contains a protein of the coronavirus, and the body becomes prepared to recognise and launch an immune response against this. This differs from vaccines like Covaxin, which contains the whole virus but in an inactivated form.
- Corbevax contains the receptor binding domain — a region of the spike protein of the SARS-CoV-2 virus that helps it infect the host cell.
- Corbevax uses a recombinant protein-based technology — a proven technology that has been in use since the 1980s and is used in the Hepatitis B vaccine. The technology involves using genetic engineering to insert a DNA code that allows a harmless microbe, such as yeast, to grow the desired protein.
- For Corbevax, researchers have used the yeast Pichia pastoris to grow the receptor binding domain of the SARS-CoV-2 virus. The yeast does not cause a disease in humans, but the body learns to recognise the protein of the coronavirus. If the body encounters the real virus in future, it will immediately recognise the receptor binding domain and launch an attack.
- As this vaccine — unlike Covaxin — contains only a part of the virus, it also needs an adjuvant, which is something added to vaccines to make the immune response stronger.
- The vaccine developed by US-based company Novavax will be produced by the Pune-based Serum Institute of India under the name Covovax.
- It is also a recombinant protein-based vaccine.
- To develop the vaccine, researchers selected a part of the genetic sequence of the virus that produces the spike protein. This sequence was then introduced in baculoviruses — pathogens that attack insects. So, the difference from Corbevax is that instead of using yeast, this vaccine uses baculoviruses.
- These modified baculoviruses were then made to infect moth cells in the lab, so that the cells produced proteins that are similar in structure to the SARS-CoV-2 spike protein.
- Along with the two new vaccines, India has also approved Molnupiravir - an antiviral that its makers say can treat people with mild and moderate Covid disease.
- Thirteen companies in India are set to manufacture this drug, including Cipla and Dr Reddy’s.
Molnupiravir, recently seen in news, is:
(a) A fruit ripening substance
(b) An anti-viral drug to treat Covid disease
(c) A pesticide to treat fungal infection in wheat
(d) An invasive plant species that can tolerate high temperature and moisture