There's at least a baseline of tests from activities which require a negative test report. For example, traveling to canada requires a negative covid test befor

There's at least a baseline of tests from activities which require a negative test report. For example, traveling to canada requires a negative covid test before crossing the border, so I'd expect vaccinated people to get tests at at least that baseline. I do agree this data would be more compelling and reliable if we did covid tests of a random sample of the population and compiled infection data from that, entirely removing any self-selection bias.