Remember the long period of time it took the U.S. to come up with a reliable covid test kit while the virus is running rampant in
China? And even when it was finally made available in those early days, from what I've gathered here, most Americans would find it almost impossible to even get tested.
I think it could be a deliberate attempt to hide the fact that the virus, possibly of a particular variant, was already circulating in the U.S.
The delay in the production of test kits could also be due to the difficulty in coming up with a test kit that can detect only a certain variant but not the other i.e. a test kit which would further help in hiding the extent of the pandemic in the U.S.