In detecting Omicron, we have a key advantage, by a stroke of luck. For many variants, scientists need to sample the full sequence to clearly distinguish them. Like a few other variants, Omicron has a particular genetic signal that shows up in PCR testing, making it easier to track with our regular testing infrastructure and easier to include tracking this variant as part of a mass testing effort.

South Korea demonstrated the importance of early mass testing. Its first Covid case was announced the same day as the first one in the United States, Jan. 20 of last year. Weeks later, a superspreader event at a South Korean church made it the first country to have a significant outbreak outside of China. Its dense cities and crowded public transportation made it a perfect place for an epidemic to bloom.

However, they were ready with a huge testing system, including free drive-through tests, and aggressive tracing. By the end of March, they had gotten the initial outbreak under control. As of now, the country of over 50 million has had a total of about 3,500 deaths during the entire pandemic — less than a week’s terrible toll in New York during its peak wave in April 2020.

The United States already needs to test more, because of the ongoing Delta surge.