The study is here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7354354/ The conclusion reads: Blood type is not associated with risk of progression to severe disease requiring intubation or causing death, nor is it associated with higher peak levels of inflammatory markers. Patients with blood types B and AB who received a test were more likely to test positive as were those who are Rh+ positive, and blood type O was less likely to test positive. This part highlights the blood type A discrepancies with previous studies: Blood type O had the lowest frequency of disease positivity, similar to Zhao et al., but blood type A had a lower frequency than blood types B and AB . Both Zhao et al. and Zietz and Tatonetti, in … Continue reading New study suggests blood types B, AB and Rh positives at highest COVID-19 risk