A June 15 study from U.K.-based Zoe Health examined the symptoms of more than 62,000 positive COVID-19 tests between June 1 and Nov. 27, 2021, when the delta variant was dominant, and Dec. 20, 2021, to Jan. 17, when the omicron variant was dominant.
Three key findings:
- Omicron symptoms lasted for shorter periods than delta symptoms: 6.87 days and 8.89 days, respectively.
- Loss of smell appeared in less than 20 percent of omicron cases and often days after the first symptoms began.
- Omicron is found less frequently in lower respiratory tracts, which can cause severe symptoms.