> There are obviously many other factors to consider [from the article] If "effectiveness" is currently being measured as reducing symptoms, could Vitamin D le

> There are obviously many other factors to consider [from the article] If "effectiveness" is currently being measured as reducing symptoms, could Vitamin D levels be a likely additional factor, known to correlate with ethnicity? Could "low Vit D" plus "no vaccine" be additive toward increased symptoms? Based on a quick scan of the preprint I see no reference to Vit D.