People with blood type A may be more vulnerable to the new coronavirus that causes Covid-19 infection, while those with blood type O seem to be more resistant.
South China Morning Post reported that this finding is according to a preliminary study of patients in China who contracted the disease.
But the study has not been peer reviewed, and the authors cautioned that there could be risks involved in using the study to guide current clinical practice.
Blood type A showed higher rate of infection
Blood type A patients showed a higher rate of infection and they tended to develop more severe symptoms, the paper published on Medrxiv.org on March 11 said.
In contrast, “blood group O had a significantly lower risk for the infectious disease compared with non-O blood groups”.
Of 206 patients who had died from Covid-19 in Wuhan, 85 had type A blood.
This rate of fatal infection was 63 per cent more than the 52 with type O.
The pattern apparently existed across different age and gender groups in the study, after blood group patterns of more than 2,000 patients infected with the virus in Wuhan and Shenzhen were taken and compared with the local healthy populations.
Blood type difference has been observed in other infectious diseases, such as SARS (severe acute respiratory syndrome).
More work needs to be done to study blood types
The researchers noted that the study was preliminary and more work was needed.
But they did urge governments and medical facilities to consider blood type differences when treating patients with the virus, known as Sars-CoV-2.
The researchers were led by Wang Xinghuan with the Centre for Evidence-Based and Translational Medicine at Zhongnan Hospital of Wuhan University.
The study was conducted by scientists and doctors from Beijing, Wuhan, Shanghai and Shenzhen.
“People of blood group A might need particularly strengthened personal protection to reduce the chance of infection,” Wang wrote.
“Sars-CoV-2-infected patients with blood group A might need to receive more vigilant surveillance and aggressive treatment.”
How blood types were discovered
Scientists are still unsure how different blood groups evolved, but they are determined by a so-called antigen, which is a material on the surface of red blood cells that can trigger an immune response.
The discovery of blood types A, B, AB and O in 1901 allowed for safe blood transfusions by matching blood types in patients.
But one theory is that blood groups are a genetic memory of plagues.
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