Serum Institute's Covishield and Bharat Biotech's Covaxin are the two available vaccines against COVID-19 in India.
In curbing the spread of the pandemic, vaccination drives have been open for 18+. Sputnik V got approval from the Government of India as the third vaccine in April 2021.
Therefore vaccines for coronavirus available in India are Covishield, Covaxin (both are in use), and Sputnik V (approved for use).
Let us first study how both the vaccines will work?
Covishield vaccine is developed by AstraZeneca and the University of Oxford. It is the Indian variant of AZD1222. Covishield vaccine is developed and manufactured by the Pune-based Serum Institute of India(SII) through a license from AstraZeneca and Oxford. That is it is a Recombinant Chimpanzee Adenovirus vector vaccine (Covishield), encoding the SARS-CoV-2 Spike (S) glycoprotein with technology transfer from AstraZeneca/Oxford University.
The vaccine is a "non-replicating viral vector" that is it makes use of another weakened and genetically modified virus. It carries the code to make the spike protein that is the spike on the surface of the virus. It is supposed that the immune system of the body will recognise this protein as a threat and work on building antibodies against it.
Now, the Covaxin vaccine, developed by Hyderabad-based Bharat Biotech in collaboration with the National Institute of Virology and uses a different platform.
Covaxin is an "inactivated" vaccine that uses the killed SARS-CoV-2 virus and has no potential to infect or replicate once injected and just serves to uplift an immune response. It is expected to target more than just the spike protein. It aims to develop an immune response to the nucleocapsid protein which is the cell of the virus that encloses its genetic material.
What does the approval mean?
Covaxin granted a restricted-use authorization in clinical trial mode and Covishield has been allowed for restricted use in emergency situations that can potentially prevent the infection of coronavirus in people aged 18 years and above.
Trial and efficacy of Covishield and Covaxin
As per DCGI, the Serum Institute submitted the data of the Phase I clinical trial which was conducted over 23, 745 overseas participants and shows an overall result of 70.42 efficacy. In India, Phase-II/III was conducted on 1600 participants and the data was found comparable with the data from the overseas clinical studies. The clinical trial ongoing in the country by the firm and will continue.
On approx. 800 participants, Bharat Biotech conducted phase one and two trials and also conducted several animal trials. The results have demonstrated that the vaccine is safe and provides a robust immune response. Its third trial is going on and about 22, 500 participants took part in it. As per the data available till date the vaccine has been found effective and safe.
According to the Indian Express, All India Institute of Medical Sciences Director Dr. Randeep Guleria "This (approval for Covaxin) is like a back-up. If we find that cases don’t rise, then we stick to the SII (Serum Institute of India’s Covishield), till the Bharat Biotech data comes early next month. And if that data is found to be good enough, then they will get the same approval as the SII. Indirectly, looking at the safety profile, that (Covaxin) is a safe vaccine, although we don’t know how efficacious it is. They (the regulators) have given, I would say, a green signal to start stockpiling in case we need it.”
On 16 January 2021, India began administering COVID-19 vaccines to win the fight against the pandemic. As per the Ministry of Health and Family Welfare, a total of 19,85,38,999 people have been vaccinated in India (as of 24 May, 2021). Also, India aims at vaccinating 250 million 'priority people' by the end of July 2021.
About Covishield and Covaxin Doses and storage temperature
Both the vaccines have to be administered in two doses and are to be stored at 2-8 oC.
Dose schedule of both the vaccines
The time interval has been extended between the two doses of the Covishield vaccine from four-six weeks to four-eight weeks. Whereas the second dose of Covaxin can be taken four to six weeks after the first.
In the last let us have a look at the Novel Corona Virus-2019-nCov-Vaccine
It is developed by M/s Cadila Healthcare Ltd. by using DNA platform technology. In India, the firm initiated Phase I/II clinical trial in more than 1000 participants which is still ongoing. The data suggest that the vaccine is safe and immunogenic with three doses when administered intradermally.
The firm also received permission to conduct Phase-III clinical trials in 26,000 Indian participants as recommended by the Subject Expert Committee.
So, now you may have come to know about the Covishield and Covaxin Vaccine.
Source: PIB, IE