Only Genomic Sequencing can do that, and it simply is too expensive and not widely available for them to make the claims they are making about "the spread of the Delta variant."
Calif has state and research labs that are capable of sequencing, as do most state labs. Don’t forget a private research lab down around Temecula soCal sequenced the original version within days of China’s belated disclosure. Can’t remember the name but it made headlines for a few days