Chinese study done in late JAN2020. N=2000+ Basically folks with blood group A have significantly higher chance of getting COVID19 than non A groups. Folks with blood group O have significantly lower risk of infection for COVID19 than non O groups.
Study here:
https://www.medrxiv.org/content/10.1101/2020.03.11.20031096v1.full.pdfConclusion here:
Conclusion
In summary, we for the first time report a link between COVID-19 susceptibility
and the ABO blood group, demonstrating the latter to be a biomarker differentiating
the former. Specifically, people with blood group A have a higher risk whereas people
with blood group O have a lower risk for SARS-Cov-2 infection and COVID-19
severity. This study may have potential clinical implications given the current
COVID-19 crisis: (1) People with blood group A might need particularly strengthened
personal protection to reduce the chance of infection; (2) SARS-CoV-2-infected
patients with blood group A might need to receive more vigilant surveillance and
aggressive treatment; (3) It might be helpful to introduce ABO blood typing in both
patients and medical personal as a routine part of the management of SARS-CoV-2
and other coronavirus infections, to help define the management options and assess
risk exposure levels of people. It should be emphasized that due to the imitations
discussed above, one should be cautious to use this study to guide clinical practice at
this time. This study encourages further studies.
Hotspot Yo, where ya been? 
