Let us know more about these two new vaccines.
Covovax:
Using the technology of Novavax vaccine developed in America, Pune based Serum Institute of India has prepared the Covovax. It is a two-dose intramuscular vaccine. This vaccine has to be stored at 2 to 8 degrees centigrade temperature. It is marketed in 0.5 ml (single-dose) and 5 ml (10 doses) vial pack. Adults above 18 years of age can benefit from this vaccine.
Corbevax:
The Corbevax vaccine is also an intramuscular jab. It is a two-dose vaccine. Corbevax was developed by Hyderabad-based biopharmaceutical firm Biological E., the Baylor College of Medicine in the US, and US-based company Dynavax Technologies. It also has to be stored at 2 to 8 degrees Celsius. It will be available in 0.5 ml (single dose) and 5 ml (10 doses) vials. It is also meant for 18 years and above.
Genetic trick:
Both Covovax and Corbevax are protein subunit vaccines. These vaccines use the proteins that the spikes on outer surface of Coronavirus are made up of. When injected into our body, the spike proteins in these vaccines teach our body to develop antibodies against the novel Coronavirus. Spike proteins are harmless as they are injected without the virus. They trick the immune system into believing that it is under attack from the real virus. The antibodies generated by them fight the real virus.
Different medium:
To develop the Covovax vaccine, researchers introduced a part of the genetic sequence producing spike protein of the virus into baculoviruses, the pathogens that only attack insects. These modified baculoviruses were then made to infect moth cells in the lab, for production of proteins similar to the spike protein. These proteins were extracted and purified for use in vaccine.
Corbevax uses a recombinant protein-based technology earlier used to make Hepatitis B vaccine. Using genetic engineering a DNA code is inserted into a harmless microbe like yeast, to grow the desired protein. The yeast does not cause a disease in humans, but the body learns to recognise the protein of the coronavirus.
Effectivity:
Basing on promising results in phase 1 and 2 trials, in June 2021 the Ministry of Health had permitted Biological E to conduct phase 3 clinical trials of Corbevax. The data from phase 3 trials have not been made public yet. In case of Covovax, Serum Institute of India claimed in June last year that it can show 90 per cent efficacy in preventing symptomatic infection from Covid-19.
