Depopulation.

Control of movement. Increasing autoimmune disease. Submission to authority. Depopulation. Etc etc etc

It's for the visitors. The planet is under quarantine and before we can head out warping to other systems we shouldn't be taking dangerous pathogens with us. Why would you call a vaccine program "operation warp speed" after everything is in line to be warping space time and using conventional rockets for landing on planets. We're supposed to join in on figuring out the universe.