Explained: Why Covaxin dose gap not increased like Covishield?

New Delhi : Days after ICMR announced increasing time gap between two doses of COVID-19 vaccines, the debate was on why it has not been increased for Covaxin, but for Covishield. Firstly, two doses were to be administered between a time gap of four to six weeks; later it was revised to eight weeks and now it has been increased to 16 weeks.

The change in time gap is for Covishield. Covaxin two dose gap remains four to six weeks.

Explaining the difference, Indian Council of Medical Research chief Dr Balram Bhargava has recently said that the decision to extend the gap for Covishield and not to extend the gap for Covaxin has been determined by the effectiveness of the first dose of the vaccine.

According to him, first dose of Covishield creates better immunity which remains effective for up to 12 weeks but this is not the case with Covaxin.

Terming it as evolving science, Dr Bhargava said vaccines came for the first time in the world on December 15 and so new developments are coming and will continue to come. "It has been seen that the first dose of Covishield results in a great deal of protection, which can stay around 12 weeks. But you do not achieve a similar kind of protection after the first dose of Covaxin. It is only after both the doses of Covaxin are administered, the protection reaches the optimum level," Dr Bhargava said.

For the same reason, people recovering from coronavirus have also been asked to delay the vaccination.