Millions of Brits could get an early fourth dose of Covid vaccine after a study suggested the booster effect against getting Omicron starts fading in as little as 10 weeks.
UK government advisors have already said a fourth dose of vaccine for some people is likely, with a decision in the new year.
And they’ve suggested the fact that third doses were rushed out could mean the gap before a fourth dose has to be shortened.
Now the UK Health Security Agency has suggested booster protection against Omicron “wanes more rapidly” than against Delta.
Around 10 weeks after a booster dose, protection against symptomatic disease with Omicron is “about 15-25% lower” than against Delta, early UKHSA analysis said.
The UKHSA added: “There is evidence that protection against symptomatic disease wanes after the second dose of vaccine, and then improves after the booster.
“But the latest data suggests this extra protection starts to wane more rapidly against Omicron than Delta, being about 15-25% lower from 10 weeks after the booster dose.”
The UKHSA stressed the booster is “more likely” to remain effective against the most severe hospital cases of Omicron.