Science behind Corbevax and how new Covid-19 jab may impact vaccination drive

Corbevax is not the only vaccine that teaches the immune system to make antibodies using the spike proteins, Novavax is another such candidate in development.

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Science behind Corbevax and how new Covid-19 jab may impact vaccination drive
The order is expected to be rolled out between August and December. (Photo: Getty)

Developed by Hyderabad-based vaccine-maker, Biological E, Corbevax is anticipated to be the next made-in-India jab against Covid-19. The government has already placed an order for 30 crore doses of the vaccine and Biological E has claimed it could have a 90 per cent efficacy against coronavirus.

The vaccine is yet to receive approval from the drugs regulator in India. However, it is being taken into account positively in the planned mammoth inoculation drive in the country. Biological E recently indicated that Corbevax could be the cheapest vaccine in the market.

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The vaccine, if and when approved, will be the third home manufactured after Serum Institute of India's Covishield and Bharat Biotech's Covaxin, which are currently driving the inoculation across India. The third vaccine approved in India is the Russian jab, Sputnik V.

Vaccines like Pfizer and Moderna work on mRNA technique or made from inactivated SARS-CoV-2.

What technology has been used to develop Corbevax?

The Corbevax vaccine has been developed using a specific part — spike protein — of SARS CoV-2 or Sars-2, the coronavirus that causes Covid-19. It has been designed using the same technology used for developing Hepatitis B vaccines.

Corbevax is, thus, a “recombinant protein subunit” vaccine that injects the spike protein that helps in generating an immune response in advance. Since the spike protein is without the virus, the body uses the antibody generated to fight the real virus when it attempts to infect the system.

Biological E has said Corbevax vaccine could be the cheapest jab against Covid-19 in India.

Corbevax is not the only vaccine that teaches the immune system to make antibodies using spike proteins, Novavax — made in India by the Serum Institute — is another such candidate in development.

How was Corbevax developed?

Studies on the recombinant vaccine began at the National School of Tropical Medicine, where scientists have been working on it for over a decade. To develop a vaccine against Covid-19, the work began in February 2020, when the genetic sequence for SARS-CoV-2 was provided. Scientists first recovered the gene sequence for the spike protein from the virus, which was put in yeast to be engineered for developing its copies.

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An adjuvant — helping substance used to develop a vaccine — was then used to stimulate an immune response. The production was then transferred to the Hyderabad-based Biological E for manufacturing and trial.

Corbevax teaches the immune system to make antibodies using spike proteins.

While other vaccines like Pfizer and Moderna work on mRNA techniques or are made from inactivated SARS-CoV-2, Corbevax, just like Covishield, attempts at segregating and using the spike proteins from the virus to trigger an immune response in the body.

Vaccine price and rollout

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The criticality of the demand for inoculating people across India can be understood from the government’s move to place an advance order for 30 crore doses of the vaccine even before it is approved by the drug controller or the Indian Council for Medical Research (ICMR).

While the third phase of clinical trials for the vaccine has been approved by the company, it is expected to be complete by July. If everything goes as anticipated, the first batch of the Corbevax vaccine may roll out in August. About 7.5 crore doses of Corbevax are expected to be available by September.

A cheaper vaccine would help the government expand its vaccination drive significantly.

Biological E has said the Corbevax vaccine could be the cheapest jab against Covid-19 in India. Speculation is that Corbevax could cost around Rs 150-200 per dose. Sources earlier told India Today TV that the negotiated cost of each Bio-E vaccine dose could be Rs 150 or less.

While the government is negotiating a deal with other vaccine makers such as Serum Institute and Bharat Biotech, a cheaper vaccine from Bio-E would help the government expand its vaccination drive significantly.