“Many of the first reported cases of Omicron variant infection appear to be mild, although as with all variants, a lag exists between infection and more severe outcomes, and symptoms would be expected to be milder in vaccinated persons and those with previous SARS-CoV-2 infection than in unvaccinated persons. Characteristics of the cases described in this report might also not be generalizable because case findings might be associated with individual characteristics (e.g., persons with recent international travel might be more likely to be younger and vaccinated).”
“Even if most infections are mild, a highly transmissible variant could result in enough cases to overwhelm health systems. The clinical severity of infection with the Omicron variant will become better understood as additional cases are identified and investigated. Scientists in South Africa and elsewhere have established systems that allow study of the laboratory, clinical, and epidemiologic characteristics; CDC is collaborating with health officials around the world to learn more about the characteristics of patients with Omicron variant infections” – CDC report.