It is not sustainable to give Covid-19 booster shots every three to six months in the long term, Britain's chief scientific adviser has said, reports Reuters.

“It would be a situation that isn't tenable to say everyone's going to need to be having another vaccine every three or six months. That's not the long-term view of where this goes to,” Patrick Vallance said at a news conference, according to Reuters.

However, he said, annual booster shots against Covid-19 might be necessary, similar to flu shots.

“We needed to get boosted for this variant at this moment. So I think there'll be a change over time and this will settle into a much more routine type of vaccine programme.”