The Drugs Controller General of India (DCGI) has given its approval for conducting a study on the mixing of Covaxin and Covishield Covid-19 vaccines in India, news agency PTI reported. The study will be conducted by the Christian Medical College (CMC), Vellore.
An expert panel of the Central Drugs Standard Control Organisation (CDSCO) on July 29 had recommended granting permission for conducting the study.
The trial will involve 300 healthy volunteers.
Mixing Covishield and Covaxin, the two main vaccines against Covid-19 in use in India, has found by a new ICMR study to be safe and also to provide better immunity. The two use different platforms: Covishield is an adenovirus vector platform-based vaccine, while Covaxin is an inactivated whole virus vaccine.
Worldwide, studies are under way to understand if a combination of two different vaccines can outperform two doses of the same vaccine. Experts caution, however, that mixing should not be randomly done but should be based on understanding multiple issues.
The study was the result of a mistake. In May, 18 villagers in Uttar Pradesh, had got Covaxin as the second dose, six weeks after they got Covishield. The study compared the vaccine response of these 18 individuals to that of 40 recipients of two doses of Covishield, and 40 recipients of two doses of Covaxin.
“Overall, this study demonstrates that immunisation with a heterologous combination of an adenovirus vector platform-based vaccine followed by an inactivated whole virus vaccine is safe and elicits better immunogenicity than two doses of homologous vaccination, using the same vaccines,” the study said.
Covaxin and Covishield are the first two vaccines which were approved by the DCGI for the nationwide inoculation drive, which began on January 16. Covaxin, developed by Hyderabad-based Bharat Biotech International Limited, is India’s first and thus far only indigenous anti-Covid shot. The Oxford University-AstraZeneca shot, on the other hand, is being manufactured locally as Covishield by Pune-based Serum Institute of India (SII). Besides these, three other vaccines, too, have been approved by the DCGI to be used in the country.
