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 [13]. Both Zhao et al. and Zietz and Tatonetti, in their preliminary data, show correlation between blood type A and likelihood of positive testing and blood type O and likelihood of negative testing [13, 14]. The finding related to blood type O appears to correlate across our study and that of both Zhao et al. and Zietz and Tatonetti, but the blood type A correlation was not found in our study [13, 14]. This association of blood type O being less common in infection is the same as that found for SARS-CoV-1 [17]. The Rh+ association with disease positivity appears to be a novel finding and warrants further investigation. Given the relative rarity of rhesus negative blood types, these could not be stratified out by blood type given our patient numbers in this study.
I have bolded the part interesting to those looking for information related to the Rh factor.
This is my video:
See also: