In this study, researchers examined the blood types of Wuhan patients infected with SARS-CoV-2 with the blood types of healthy citizens in the surrounding area. They found that COVID-19 infections were more common among people with type A blood and less frequent in people with type O blood. This is an early study. Regardless, it should encourage more researchers to study the link between blood type and COVID-19 infection rate.
Past studies have shown that traits such as age, gender, and health conditions may affect how likely a person is to contract COVID-19. However, there is currently no known component in the human body that can be used to reliably predict how susceptible a person is to COVID-19. Other viruses like Hepatitis B are known to infect people with specific blood types more often. Blood types are distinguished by the different antigens that blood cells of different types have. In this study, researchers wanted to see if there are specific blood types that affect the risk of contracting COVID-19.
Typed blood samples were collected from living and dead COVID-19 patients from the cities of Wuhan and Shenzhen in China. These COVID-19 cases were confirmed using reverse PCR tests. Surveys were also sent out to healthy citizens in Wuhan and Shenzhen asking them to provide their blood types. The blood types of infected and healthy citizens were compared using statistical methods.
A significantly higher proportion of infected people, living and dead, had the A blood type. Meanwhile, a significantly higher proportion of healthy people had the O blood type. The percentage of people with blood types B and AB were similar between the two groups. These percentages remained constant even when the researchers compared different age and sex groups.
The data suggests that different blood types confer different levels of risk for COVID-19 infections. Type A blood is associated with greater risk while type O blood is associated with lower risk. Future studies should aim to investigate the mechanisms driving these different levels of risk.
The number of people examined in the study was small. Some of the people also had unknown ages, sexes, and chronic medical conditions.
This study provides the first reported link between blood type and COVID-19 risk. However, it should be verified with future studies that examine more people. If verified, the study's results could change how we handle the pandemic. People with type A blood may be given more personal protection against infection. Infected people with type A blood may need to receive more aggressive treatment. Blood types may receive higher consideration in COVID-19 management efforts.