According to the study conducted by the Indian Council of Medical Research (ICMR), the cocktail vaccine formed by mixing and matching of Covaxin and Covishield has shown better results in providing better immunity against the variant strains of coronavirus i.e. SARS-CoV-2. It has also been tagged as ‘safe’ for use by the ICMR.
The study was conducted between May and June this year in the state of Uttar Pradesh. The study suggests that immunization with a combination of an adenovirus vector platform-based vaccine i.e. Covishield followed by inactivated whole virus vaccine i.e. Covaxin was not only safe for the patients but also built better immunity against the virus.
The study suggests, “Such mixed regimens will also help to overcome the challenges of shortfall of particular vaccines and remove hesitancy around vaccines in people’s mind that could have genesis in programmatic ‘errors’ especially in settings where multiple Covid-19 vaccines are being used.”
On July 30, a Subject Expert Committee of the Central Drugs Standard Control Organisation (CDSCO) advocated for conducting a study on mixing doses of Covishield and Covaxin vaccines. The recommendation came after an application by Christian Medical College (CMC), Vellore. While discussing the application, the CDSCO panel suggested that CMC should conduct clinical trials on this. The expert panel also recommended the mixing of Bharat Biotech’s Covaxin and a nasal vaccine (BBV154) candidate that has been developed for use in children.
The study conducted by ICMR is yet to be reviewed by the other peer institutes.
Recently, The Drugs Controller General of India (DCGI) has also given its approval to CMC, Vellore for a study on the mixing of Covaxin and Covishield Covid-19 vaccines in India. It has also recommended CMC conduct a phase-4 clinical trial covering 300 healthy volunteers.
The purpose of this study would be to assess whether a person can be given two different vaccine shots – one each of Covishield and Covaxin, in order or complete the course of vaccination.
WHO on the mixing of Covid vaccines
In July this year, WHO chief scientist Soumya Swaminathan warned against the mixing and matching of Covid-19 vaccines from different manufacturers and even called it a “dangerous trend” since there was not much data available on this aspect.
Soumya Swaminathan said, “So it’s a little bit of a dangerous trend here. We’re in a data-free, evidence-free zone here as far as mix-and-match. There is limited data on mix and match. It will be a chaotic situation in countries if citizens start deciding when and who will be taking a second, a third, and a fourth dose.”