list from CDC report on US cases

The Centers for Disease Control and Prevention on Friday released new data about the omicron variant of COVID-19 based on 43 cases in the United States. While the sample is small and it’s still too early to tell how the variant will behave—the extent to which it will evade vaccine protection, spread more rapidly, or outcompete the delta variant—the data offers an early glimpse at the newest variant of concern, as designated by the World Health Organization (WHO) on November 24. Here are some of the key findings: 

Cases, demographics, details

The report looks at details from 43 known omicron cases in the United States, with the first symptom being reported on November 15. 

Of those 43 cases: 

  • 25 were people between 18-39
  • 10 were people between 40-64
  • 14 reported traveling internationally within 14 days before symptoms or a positive test result
  • 34 were fully vaccinated
  • 14 received a booster (5 of those received a booster less than 14 days before symptom onset
  • 9 were unvaccinated
  • 6 people had been previously infected with COVID-19
  • 1 person was hospitalized (for two days)
  • 0 people have died

Where and how is it spreading? 

The CDC report was based on follow-up on cases reported between December 1 – December 8 in 22 states. The agency’s investigations revealed transmission associated with large events, international travel, and households.

What symptoms are being reported? 

According to the report, 40 of the 43 people developed symptoms. These were the most common: 

  • Cough (89%)
  • Fatigue (65%)
  • Congestion or runny nose (59%)
  • Fever (38%)
  • Nausea or vomiting (22%)
  • Shortness of breath / difficulty breathing (16%)
  • Diarrhea (11%)
  • Loss of taste / smell (8%)

Note that this small sample should not be read as representative of the entire population. As the CDC points out, findings in the report may reflect characteristics of this particular group, more than half of whom were under 40 and the majority of whom were fully vaccinated. It’s still too early to tell if omicron cases will be milder on average than other variants over the long term.

Like other variants before it, the emergence and rapid spread of omicron around the world has underscored the importance of genetic surveillance. According to the CDC, 50,000–60,000 positive COVID-19 specimens are sequenced each week on average as part of national surveillance efforts. So we’ll know a lot more about omicron as more data comes in. 

You can check out the full report here.