This ZOE business is something else. Their website is 75% building up their credentials, 25% promoting their app and 0% substance, e.g. what the actual formulas are or a link to code and data dumps. Or at least a research publication with some details. Perhaps there is a link hidden somewhere, but neither their Home, About or FAQ point to it.

They literally changed their formula because the trends in the unvaccinated population didn't to conform to their prior biases. Though the formula details are still a mystery.

"Last week, we reported a plateau in new COVID cases based on our methods at the time, which relied on a small number of unvaccinated people in our dataset compared with the wider UK population. The number of daily new cases in the unvaccinated group appeared to be dropping which in turn resulted in our overall numbers trending down. This meant the figures were accurate to our dataset but didn’t represent the full picture in the UK."

https://covid.joinzoe.com/post/covid-estimates-updated-vacci...

I'll grant that UK has no vaccine mandates (including for kids!) and none of the craziness. Have a great one!