More clinical and real-world data is needed on how well and for how long Covid-19 vaccines are protective before any decisions should be made on offering a third or booster doses, Europe's drug regulators have said.

Speaking at the first of planned regular fortnightly media briefings on the coronavirus pandemic, the European Medicines Agency's head of biological health threats and vaccines strategy Marco Cavaleri cautioned against making “premature” moves to deploy booster Covid-19 shots.

“We need to look into real-world evidence [...] to give us the data we need to know when would be the right time to give a third dose,” he said.