The Omicron coronavirus variant could be just as severe as the Delta strain, according to early findings from researchers at Imperial College London, in a study which also highlighted the elevated risk of reinfection posed by the new variant and the need for booster shots to combat it.
“The study finds no evidence of Omicron having lower severity than Delta, judged by either the proportion of people testing positive who report symptoms, or by the proportion of cases seeking hospital care after infection,” said the research team, led by Professor Neil Ferguson, an infectious disease modeller and government science adviser.
However, they cautioned that hospitalisation data “remains very limited at this time”. The study said data suggested “at most limited changes in severity compared with Delta”.
The early findings could dash the hopes of some experts that a change in the virulence of the new variant would ease the pressure on health systems despite Omicron’s high levels of infectiousness.
Professor Azra Ghani, an epidemiologist at Imperial College London and one of the study’s authors, stressed the “uncertainty” surrounding whether or not Omicron is less severe than previous strains.
“Whilst it may take several weeks to fully understand this, governments will need to put in place plans now to mitigate any potential impact,” she said, adding that the results demonstrated “the importance of delivering booster doses as part of the wider public health response”.