The cdc has a statement o. Their website stating that there is no test to detect any variant of covid. If this is true, then how do these studies determine who has variants and how prevalent they are?
Either they estimated the Omicron/ Delta mix or the Danes are smarter. Or they made it up.
As I understand it, variants have to be identified by genetic sequencing beyond a regular test (which is expensive and takes time), and a certain percentage of tests are automatically evaluated via sequencing.