Two recently published studies have shown that people with blood group O may have a lower risk of Covid-19 infection and reduced likelihood of severe outcomes, including organ complications, if they do get sick.
As the pandemic lingers, the global biomedical research community is working to pinpoint coronavirus risk factors and possible curative targets. The potential role of blood type in predicting risk and complications of coronavirus infection has emerged as a significant scientific question. These new studies add to evidence that there may be an association between blood group and vulnerability to the novel virus; however, further research is needed to understand why and what it means for patients.
According to a new study, blood group O may offer some protection against Covid-19 infection. Researchers made a comparison between Danish health registry data of more than 473,000 persons tested for coronavirus and data from a control group of more than 2.2 million individuals from the general population. Among the Covid-19 positive results, they found fewer people with blood group O and more people with blood groups A, B, and AB.
The study results suggest that people with blood groups A, B, or AB may be more likely to be infected with the virus than people with group O. The researchers did not find any major difference in the rate of infection among blood groups A, B, and AB. Since blood group differ among ethnic subgroups, they also controlled for ethnicity and maintained that less people with blood group O tested positive for the virus.
Study author, Dr. Torben Barington of Odense University Hospital and the University of Southern Denmark said it is very important to consider the appropriate control group because blood type prevalence may differ considerably in different ethnic groups and countries.
Earlier this year, a study of more than two thousand coronavirus patients in China found that, of the 206 people who died, 85 had blood group A – which is equivalent to 41% of all deaths. It also showed they were more vulnerable to infection and inclined to have more severe symptoms. Those with blood group O had a "significantly lower risk" of contracting the disease. The Chinese team advised medics and governments to consider blood type differences when treating patients with the virus.
According to a separate study, it showed that blood groups A and AB were associated with increased risk of severe clinical outcomes of Covid-19 infection. Individuals with blood groups A or AB displayed greater severity than people with blood groups O or B. Researchers examined data from ninety five critically ill Covid-19 patients hospitalized in Vancouver, Canada. They found that patients with blood groups A or AB were more likely to need mechanical ventilation, proposing that they had higher rates of lung injury from Covid-19. They also found out that more patients with blood group A and AB needed dialysis for kidney failure.
Together, these findings suggest that patients in these two blood groups may have a higher risk of organ dysfunction or failure as a result of Covid-19 than people with blood groups O or B. Also, while people with blood groups A and AB did not have longer overall hospital stays than those with groups O or B, they did remain in the intensive care unit (ICU) for a longer average time, which may also indicate a greater Covid-19 severity level.
Dr. Mypinder Sekhon, the lead author, of the University of British Columbia, said that the distinctive part of their study is their focus on the severity effect of blood type on Covid-19. They observed the lung and kidney damage, and in future studies, they will unravel the effect of blood group and Covid-19 on other vital organs.
Advice is still to wash your hands and follow the guidelines issued by the authorities, no matter your blood group.