First big Omicron study from UK was just released today (not peer-reviewed yet) from the Imperial College of London (led by well-known Neil Ferguson). Covers hundreds of thousands of people since the end of November. Major conclusions:
www.imperial.ac.uk
Study Link:
- "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. However, hospitalisation data remains very limited at this time."
- 5.4 times greater chance of reinfection compared to Delta (immunity from previous infection only 19%)
- "...vaccine effectiveness estimates against symptomatic Omicron infection of between 0% and 20% after two doses, and between 55% and 80% after a booster dose."
- The distribution of Omicron by age, region and ethnicity currently differs markedly from Delta, with 18–29-year-olds, residents in the London region, and those of African ethnicity having significantly higher rates of infection with Omicron relative to Delta

Omicron largely evades immunity from past infection or two vaccine doses | Imperial News | Imperial College London
The Omicron variant largely evades immunity from past infection or two vaccine doses according to the latest Imperial modelling.

Study Link: