He said the company already has six million booster doses of Covovax vaccine available and adults must take the booster shot.
Reacting to reports of COVID-19 vaccines shortage, he said manufacturers are ready but there has been no demand.
"Just as a precaution, at risk we have done it so that people have a Covishield as a choice if they want it," Mr. Poonawalla told PTI on restarting of manufacturing of the vaccine.
The company had stopped manufacturing of Covishield in December 2021.
On Covovax which has been approved as a booster dose for 18-years and above, he said, "We have six million doses ready but the demand is exactly zero." Covovax booster is now on the CoWin app, he said.