It targets Type A blood populations..which is higher in the West and lower in China. O is safer which is higher in China (48%).
https://en.wikipedia.org/wiki/Blood_type_distribution_by_country
https://www.webmd.com/lung/news/20200320/blood-type-may-affect-covid19-risk-study
Blood Type May Affect COVID-19 Risk: Study
March 20, 2020 -- A person's blood type may affect their risk for COVID-19, the disease caused by the
new coronavirus, researchers report.
They analyzed
blood samples from nearly 2,200 COVID-19 patients in China and tens of thousands of healthy people, and found those with
A blood types had a significantly higher risk of COVID-19 while those with
O blood types had a significantly lower risk, Newsweek reported.
The findings appear on the website medRxiv, where health researchers publish studies before they undergo the peer review process required by journals.
The researchers said blood type-related differences in COVID-19 risk may be due to certain antibodies in the blood, but further studies are needed to confirm this, Newsweek reported.
The finding that blood type may affect COVID-19 risk could be important for healthcare workers treating COVID-19 patients, because those with A blood types" "might need particularly strengthened personal protection to reduce the chance of infection."
Also, people with A blood types might require "more vigilant surveillance and aggressive treatment," and identifying a person's blood type as a routine part of treating COVID-19 and other
coronavirus infections might be helpful, according to the researchers, Newsweek reported.
The study was limited because of its small size and it didn't offer an explanation for its findings, Gao Yingdai, a researcher from the State Key Laboratory of Experimental Hematology in Tianjin, told the South China Morning Post.
The study "may be helpful to medical professionals, but ordinary citizens should not take the statistics too seriously," said Gao,who did not work on the study, Newsweek reported.
"If you are type A, there is no need to panic. It does not mean you will be infected 100 percent," she said, addingm "If you are type O, it does not mean you are absolutely safe, either. You still need to
wash your hands and follow the guidelines issued by authorities."