Vaccine policy group seeks more lab data on tests for mixing Covid doses

NTAGI has a month to go before it gives its advice to the government on inoculation strategy.

The organisation that makes India’s vaccination strategy has sought more laboratory data before it decides on advising mixing Covid-19 doses—a medical practice called heterologous boosting.

The National Technical Advisory Group on Immunisation (NTAGI) has month to go before its gives its advice to the government. It has sought more laboratory data from the Christian Medical College (CMC), Vellore, where researchers are conducting a study on mixing Covid-19 vaccines, said sources in the know.

CMC will conduct more tests on neutralising antibodies on 400 subjects enrolled for a study on testing how mixing Covaxin (a vaccine manufactured by Bharat Biotech) and Covishield (manufactured by Serum Institute of India) induced immune response in comparison to using the same vaccine as the third dose.

“The preliminary findings of the study were presented before the NTAGI, and they asked for more details and analysis. Therefore, more blood sera tests are now being done for neutralizing antibodies. This would take another two to three weeks,” said a person close to the development.

It would take at least a month before this laboratory evidence is collected and analysed, said the person cited above. The data would then be presented before the NTAGI and the Drugs Controller General of India (DCGI).

DCGI, last July, approved the CMC study on mixing vaccines The study has tested 200 volunteers who took two doses of Covishield and 200 volunteers who got two doses of Covaxin. “Of these, 100 of those who got two Covishield doses were given Covaxin as the third shot and the remaining 100 were given Covishield only as the third shot. Similar thing was repeated for 200 people who got two Covaxin doses,” Winsley Rose, principal investigator of the study, had told 'Business Standard'.

Many countries have approved mixing of vaccines, but India is yet to formalise a protocol. India has 14,307 active Covid-19 cases. It reported 1,225 daily new cases in the last 24-hours.

India has administered 21.7 million doses as precaution dose to its healthcare and frontline workers along with the senior citizens.