The finding could explain why so many people have been infected a second time during the Omicron wave, even with Omicron itself.
“Getting infected with Omicron does not provide a potent boost to immunity against re-infection with Omicron in the future,” says Professor Rosemary Boyton, an infectious disease immunologist at Imperial’s College in London who led the study of COVID in UK healthcare workers..
The results suggest infection with Omicron will not necessarily offer increased protection against the BA.4 and BA.4 sub-variants of COVID now on the increase in the UK.