Theoretically during COVID-19 pandemic numerous governments have been publishing infection data. In practice it would be hard to publish anything on this subject right now, moreover I did dare to run any SIR model for Poland (and used proxy related to timing and relative regional infection proportions), as I was skeptical about low and regionally varied detection rate.
The best what I have found so far were mortality data. Being dead is not subject to different definition and those data are quite reliably documented. The best are are weekly numbers of deaths which allow to detect passing of COVID-19 or influenza wave.
I also have seen a few terribly patchy datasets for ILI.