According to a study conducted in Qatar, a previous COVID-19 infection appeared to be less effective at preventing reinfection with the Omicron variant compared to prior variants; however, it did seem to protect against severe disease.

The effectiveness of a prior infection in preventing reinfection was 56.0% against the Omicron variant, in comparison with 90.2% against the Alpha variant, 85.7% against the Beta variant, and 92% against the Delta variant, noted researchers. Effectiveness of a previous natural infection against severe, critical or fatal illness from Omicron was found to be 87.8%. None of the reinfections resulted in death. 

The investigators report the results in a correspondence published in the New England Journal of Medicine… (Medpage Today)