The advisory committee to the European Union's drug regulator said it has recommended reducing the interval between the second dose and booster dose of Moderna Inc's Covid-19 vaccine from six months to three months, Reuters reports.

Several countries including Greece and France have previously shortened the interval between the first two doses and the booster dose of Covid-19 vaccines, in the face of rising cases due to the Omicron variant.

Some also authorised a fourth shot for the vulnerable.