Covid Vaccine: DCGI Gives Nod To Study Mixing Covaxin & Covishield

Drugs Controller General of India gives nod for conducting a study on mixing Covaxin & Covishield.

New Delhi: The Drugs Controllers of India has given its nod to study mixing Covishield and Covaxin. After a study was conducted by the Indian Council of Medical Research (ICMR) showed that combining these two COVID-19 vaccines elicited better immunogenicity than two doses of the same vaccine.

Researchers also found that mixing Covishield and Covaxin was safe and the adverse effects were similar to the same dose regimen. 

The study approved by the DCGI will involve 300 persons. Central Drugs Standard Control Organisation (CDSCO)  panel of experts on July 29, 2021, had recommended granting permission for conducting the study.

"The aim of the study is to assess the feasibility on whether a person can be given two different vaccine shots -- one each of Covishield and Covaxin -- to complete the inoculation course," a source said according to PTI. 

Meanwhile, the study by ICMR titled Serendipitous COVID-19 Vaccine-Mix in Uttar Pradesh, India: Safety and Immunogenicity Assessment of a Heterologous Regime' had been uploaded on medRxiv, a preprint server, and is yet to be peer-reviewed.

"To the best of our knowledge, this is the first study which reports the effects of heterologous prime-boost vaccination with an adenovirus vectored vaccine followed by an inactivated whole virus vaccine," the researchers said.

Primarily, India has been vaccinating its population with two vaccines - Covishield which is an adenovirus vector platform-based vaccine, and Covaxin which is a inactivated whole virion BBV152. This was followed with a homologous prime-boost approach. 

For the study, 18 individuals who had received one dose of Covishield and a second dose of Covaxin, 40 recipients of two doses of Covishield, and 40 recipients of two doses of Covaxin, were also included to compare. The study duration was from May to June 2021.

"We compared the safety and immunogenicity profile of them (18 individuals) against that of those receiving either Covishield or Covaxin. Lower and similar adverse events following immunisation in all three groups underlined the safety of the combination vaccine regime.

"Immunogenicity profile against Alpha, Beta and Delta variants in the heterologous group was superior and IgG antibody and neutralising antibody response of the participants was also significantly higher compared to that in the homologous groups," the study stated.

"The findings suggest that immunisation with a combination of an adenovirus vector platform-based vaccine followed by an inactivated whole virus vaccine was not only safe but also elicited better immunogenicity," it said.