南非早期研究发现Omicron病况不严重，很多入院的都是因其他原因入院，不得不测COVID而测出。

https://www.samrc.ac.za/news/tshwane-district-omicron-variant-patient-profile-early-features

A snapshot of 42 patients in the ward on 2 December 2021 reveals that 29 (70%) are not oxygen dependent. These patients are saturating well on room air and do not present with any respiratory symptoms. These are the patients that we would call ‘incidental COVID admissions’, having had another medical or surgical reason for admission. Thirteen (13) patients are dependent on supplemental oxygen of which nine (21%) have a diagnosis of COVID-19 pneumonia based on a combination of symptoms, clinical signs, CXR and inflammatory markers. All are being prescribed steroids as the mainstay of therapy. The remaining 4 patients are on oxygen for other medical reasons (2 previously on home oxygen, 1 in heart failure and 1 with a confirmed diagnosis of Pneumocystis Pneumonia).

This is a picture that has not been seen in previous waves. In the beginning of all three previous waves and throughout the course of these waves, there has always only been a sprinkling of patients on room air in the COVID ward and these patients have usually been in the recovery phase waiting for the resolution of a co-morbidity prior to discharge. The COVID ward was recognizable by the majority of patients being on some form of oxygen supplementation with the incessant sound of high flow nasal oxygen machines, or beeping ventilator alarms.