Lack of candidates likely to delay mixed vaccine study by a month

The Christian Medical College (CMC) mixed vaccine study, which aims to discover how a fully vaccinated person responds to a booster of another vaccine is likely to be delayed by a month due to the lack of candidates who have taken two doses of Covaxin, the study’s principal investigator Dr Winsley Rose said.

Started in September last year, the 18-month long study was able to get the required 200 participants who had taken two doses of Covishield, but to date, the study is still short of 50 candidates (of the 200 required) who took Covaxin, he added.

Dr Winsley said he was “hopeful of the remaining 50 candidates joining the study in a week.” Asked if the study was still relevant in the context of the delta and omicron variants playing havoc, sources revealed that it would reveal how candidates with two doses of one vaccine would react to a booster dose of another. “This will help the public choose which vaccine they want for a booster dose and thereby save them the problem of not having to wait till the particular vaccine was available,” sources said.

On reports that Covaxin booster doses were highly effective, he said this was yet to be fully studied as there were many cases of those who received both doses of Covaxin being affected by the virus.

Asked if any reports had been forwarded to the central government, Dr Winsley said, “This is yet to be done as the study is yet to commence fully.” However periodic progress reports were being sent to the Data and Safety Monitoring Board (DSMB), which comprises of a group of subject experts, for their perusal and instruction if any.