Not unusual at all. Excrement comes in clumps.
Ping
The CDC compromised their mission and integrity by doing this. The level for involvement between a teachers’ union and CDC should be at some subcommittee level where the CDC would be studying disease spread factors in schools/classrooms and seeking expertise by having some teachers’ unions providing some experts (along with other groups’ scientific experts like school nurses, school custodians, parents, pediatricians, ...) to collaborate with CDC experts/scientists to study issues and hypotheses.