> For Europe, the south shows an east west divide, with more vaccinated westerly countries having lower active cases than the eastern countries. However, the north shows the reverse with high active case numbers in the more heavily vaccinated countries, currently.<p>Vitamin D?<p>Because there are so many confounding factors, the best comparison is within a smaller more heterogenous population like:<p><a href="https://pbs.twimg.com/media/E-2xk8AWEAAWfaw?format=png&name=4096x4096" rel="nofollow">https://pbs.twimg.com/media/E-2xk8AWEAAWfaw?format=png&name=...</a><p>Comparing within the same state or small country reduces the likelihood of differences like climate, diet, age of population, differences in the way data is tabulated, etc.