Omicron five times more likely to reinfect than Delta: Study

The new findings could accelerate the imposition of tighter restrictions across a number of European countries. 

The risk of reinfection with the Omicron coronavirus variant is more than five times higher and it has shown no sign of being milder than Delta, a study by Imperial College London showed, as cases soar across Europe and threaten year-end festivities. The results were based on UK Health Security Agency and National Health Service data on people who tested positive for COVID-19 in a PCR test in England between Nov. 29 and Dec. 11.

"We find no evidence (for both risk of hospitalisation attendance and symptom status) of Omicron having different severity from Delta," the study said, although it noted that data on hospitalisations remains very limited.

"Controlling for vaccine status, age, sex, ethnicity, asymptomatic status, region and specimen date, Omicron was associated with a 5.4-fold higher risk of reinfection compared with Delta," the study, which was dated Dec. 16, added.