Early reports from South Africa, one of the first countries affected by omicron, showed that most cases had mild symptoms such as a sore throat and upper respiratory congestion, and often with severe fatigue (feeling very tired).
Unlike earlier variants, omicron did not seem to cause a loss of taste or smell.
According to the CDC, many factors can make a difference in how severe omicron symptoms are, and if the symptoms happen. These factors include vaccination status, having had an infection before, age and other health conditions.