Indian vaccine maker Serum Institute of India (SII) has said it had to dump 100 million doses of their Covid-19 vaccine after they expired.

The firm stopped producing Covishield in December last year due to low demand, CEO Adar Poonawalla said on Thursday.

SII, the world's largest vaccine maker, has been making the local version of AstraZeneca's Vaxzevria jab.

Covishield accounts for over 90% of the doses given in India.

India has administered over two billion doses of Covid-19 vaccines. More than 70% of the Indian population has taken at least two doses, according to the federal health ministry.

In January 2022, India began giving boosters to healthcare and frontline workers, and those above 60 years with comorbidities. It was later expanded to all adults.

In July, free booster doses - or precaution doses as the government calls it - were provided to all adults for 75 days to mark 75 years of India's independence.

But so far, India has administered just 298 million booster doses, according to the health ministry.

"The booster vaccines have no demand as people now seem fed up with Covid," Mr Poonawala told reporters on Thursday. "Honestly, I'm also fed up. We all are."

According to Mr Poonawala, the SII had around 100 million doses of Covishield in stock. The vaccines - which have a shelf life of nine months - expired in September this year.

The CEO was speaking on the sidelines of the annual general meeting of the Developing Countries Vaccine Manufacturers Network (DCVMN) in the western Indian city of Pune.

"Going forward, when people take a flu shot every year, they may take a Covid vaccine along with it," Mr Poonawala said. "But in India, there is no culture of taking a flu shot every year, like in the West."

Meanwhile, Mr Poonawala said the SII had completed trials for the Covid vaccine Covovax as a booster dose. The company expects the vaccine to get approval within the next two weeks.

It has also partnered with the US biotech company Novavax for an Omicron-specific booster, he said.