The new Omicron variant of the coronavirus poses a threefold higher risk of reinfection than the currently dominant Delta variant and the Beta strain, a group of South African health bodies said on Thursday.

The South African Centre for Epidemiological Modelling and Analysis (SACEMA) and the National Institute of Communicable Diseases (NICD) said the latest findings “provide epidemiological evidence for Omicron’s ability to evade immunity from prior infection”.

Their statement was issued after a group of South African health organisations published a paper on medrxiv.org as a pre-print, meaning the work was not yet certified by peer review.