Note: I am pausing the Q&A for the holidays, and will aim to resume on January 4th.  In the meantime, if you have questions, continue to send them along.  I wish you a happy, healthy, and joyous holiday season.

Question: My friend just tested positive for COVID.  What are the odds it’s Omicron?

Answer: I hope your friend has a speedy recovery.  The odds that the infection is due to the Omicron variant are low, and will greatly depend on where your friend lives.  According to CDC’s Nowcast model, as of December 11th, only 2.9% (95% CI: 0.2%-14.7%) of circulating variants were Omicron, but this is a big jump from the previous week when it was just 0.4%.  We’re finding that Omicron is spreading quickly; it already represents 13% of circulating variants in New York and New Jersey (Figure 1).  Just yesterday, the Washington Post reported that federal officials are warning that Omicron’s spread “could peak in a massive wave of infections as soon as January.”  To reiterate, the odds are that your friend is infected with the Delta variant, but as time progresses, we are seeing more and more infections in the US being driven by Omicron. 

Figure 1. Circulating Variants, trends and geography (from CDC)