China COVID-19 study: blood type O are more resistant, type A are more susceptible to infection

From the blood group patterns of more than 2,000 patients studied, the researchers discovered that blood type A patients showed a higher rate of infection and they tended to develop more severe symptoms

A new medical study on the coronavirus in China found that blood type A patients were more susceptible to the infection and tended to develop more severe symptoms, while patients with blood type O seemed more resistant to the disease.

Medical researchers from across China conducted a preliminary study on different blood groups and resistance to the Coronavirus Disease 2019 (COVID-19). Blood group patterns of over 2,000 patients infected with the virus in Wuhan and Shenzhen were studied and compared with that of local, healthy population.

First reported on by the South China Morning Post (SCMP), the study was led by Wang Xinghuan with the Centre for Evidence-Based and Translational Medicine at Zhongnan Hospital of Wuhan University and involved scientists and doctors from Beijing, Wuhan, Shanghai and Shenzhen.

The study found that patients from the O blood group had a “significantly lower risk” for COVID-19 and that those with blood type A may be more vulnerable and might need “particularly strengthened personal protection” against the infection.

From the blood group patterns of more than 2,000 patients studied, the researchers discovered that blood type A patients showed a higher rate of infection and they tended to develop more severe symptoms.

“Sars-CoV-2-infected patients with blood group A might need to receive more vigilant surveillance and aggressive treatment,”  wrote Mr Wang.

The study also found patients with blood type O were more resistant to the disease.

“Blood group O had a significantly lower risk for the infectious disease compared with non-O blood groups,” the researchers wrote in a paper published on Medrxiv.org on March 11.

The blood types of the 206 patients who died from COVID-19 in Wuhan, the epicentre of the virus, were studied. Of the fatalities, 85 had type A blood and 52 had type O. The type A deaths were 63 per cent more than the type O deaths. The study’s authors found that the pattern was present across various age and gender groups.

Blood types are determined by an “antigen”, which is a material on the surface of red blood cells that can trigger an immune response. The main blood groups were discovered by Austrian biologist Karl Landsteiner in 1901—type A, B, AB and O. The medical breakthrough made blood transfusions safer as patients’ blood types could be matched properly.

Head researcher Wang noted in the paper that it may be beneficial to “introduce ABO blood typing in both patients and medical personnel 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”.

The study has yet to be peer reviewed, and researchers noted that there could be risks involved in using the study as a guide for current practices.

SCMP also reported other experts reactions to the blood type study. Researcher Gao Yingdai of the State Key Laboratory of Experimental Haematology in Tianjin, commented that it could be improved with a larger sample size. Although 2,000 is not a small number, it is tiny in comparison to the total number of confirmed COVID-19 cases globally—now over 198,000 people.

Ms Gao, who was not involved with the study, noted that the study did not explain the phenomenon properly. There was no mention of the molecular interaction between the coronavirus and different types of red blood cells, said Ms Gao.

Previous studies have observed blood type differences in other infectious diseases, such as Norwalk virus, hepatitis B and severe acute respiratory syndrome (SARS).

Ms Gao acknowledged that while new study “may be helpful to medical professionals, ordinary citizens should not take the statistics too seriously”.

Researcher Gao of the Tianjin laboratory said that blood type A persons should not panic, as “it does not mean you will be infected 100 per cent”. Speaking to blood type O individuals, Ms Gao noted that “it does not mean you are absolutely safe, either. You still need to wash your hands and follow the guidelines issued by authorities.”

While the authors noted that the study was “preliminary” and acknowledged that more research was needed, they also did encourage governments and health centres to take into consideration difference in blood types for medical treatment of COVID-19 patients and when developing measures to mitigate the spread of the virus. /TISG