India's drug regulator approves study on mixing Covishield, COVAXIN jabs
The Drugs Controller General of India (DCGI) has approved a proposal to conduct a study on the mixing of Covishield and COVAXIN COVID-19 vaccines. The study was recommended by the Subject Expert Committee (SEC) on COVID-19 of the Central Drugs Standard Control Organization (CDSCO) last month. As recommended by the SEC, Christian Medical College (CMC), Vellore has been allowed to conduct the study.
What had the expert panel recommended?
Last month, the SEC had recommended the Christian Medical College (CMC), Vellore in Tamil Nadu to conduct clinical trials on mixing Covishield and COVAXIN doses. The clinical trials will reportedly be conducted among 300 healthy volunteers. The study aims to determine the efficacy against the viral disease upon inoculation of an individual with two doses from different vaccines.
No decision on mixing COVAXIN, nasal vaccine
SEC has also recommended mixing of Covaxin and Bharat Biotech's nasal vaccine, BBV154. However, the DGCI has not taken any decision on this. SEC had reportedly asked Bharat Biotech to submit a revised study protocol for its approval by removing "interchangeability" from its study title.
ICMR said mixing Covishield, COVAXIN is safe
Last week, the Indian Council of Medical Research (ICMR) indicated that the mixing and matching of Covishield and COVAXIN can yield better results. The study, yet to be peer-reviewed, was based on 18 people in Uttar Pradesh who were accidentally inoculated with two doses of the two different vaccines. The study also stated that the mixing of the two vaccines is completely safe.
Considering mixing vaccines based on same platform: NTAGI
Meanwhile, India's COVID-19 working group National Technical Advisory Group on Immunisation (NTAGI) is reportedly considering mixing different vaccines if both doses are based on similar technologies. For instance, two adenovirus-based vaccines (such as Covishield and Sputnik) can be mixed, or two mRNA-based (Pfizer and Moderna) can be mixed. Officials maintained that the final decision will be taken after considering scientific evidence.
Covishield and COVAXIN are based on two different platforms
To note, Covishield and COVAXIN are manufactured using two different technologies. While Covishield is an adenovirus-based vaccine, COVAXIN uses a whole virion that has been inactivated or killed.
What did WHO say on mixing vaccines?
Separately, in its interim recommendation last month, the World Health Organization (WHO) said a combination of recombinant vaccines like Covishield and Sputnik does not require an additional dose of either vaccine. It also said that immune responses after the first dose of a recombinant jab followed by an mRNA vaccine showed higher neutralizing antibody levels than two doses of recombinant or mRNA vaccines.