The CDC is referring to the genetic sequencing of the covid virus to determine if it's a new variant or not. The US does less genetic sequencing of the virus than other countries. That's one of the reasons why the US is not usually early in identifying the emergence of new variants even if they are present.
However, there is nothing stopping them from sequencing your DNA as well, it's just not what this tweet is referring to.
The CDC is referring to the genetic sequencing of the covid virus to determine if it's a new variant or not. The US does less genetic sequencing of the virus than other countries. That's one of the reasons why the US is not usually early in identifying the emergence of new variants even if they are present.
However, there is nothing stopping them from sequencing your DNA as well, it's just not what this tweet is referring to.
10% chance of the virus, 100% chance of sweet, sweet DNA.