SARS-CoV-2 Variants Viruses constantly change. Some emerge, only to disappear. Some emerge … and persist. Multiple COVID-19 variants have been documented around the world, including in the United States. The Centers for Disease Control and Prevention (CDC) has identified five variants of concern currently in the U.S. Our scientists have analyzed viruses for decades. Now, their work is in the spotlight as COVID-19 variants emerge. Here's how they're keeping our tests current. Many infectious disease experts anticipate the virus (and its variant offspring) will continue to circulate the globe, with outbreaks in certain areas or seasonal waves, as we see with the flu or RSV. And we have a test for that. Having accessible, rapid testing is critical to catching new outbreaks, particularly for communities hardest hit already and where vaccine accessibility may be limited.