Coronavirus: blood group plays a role, new study finds

New evidence has been found that patients’ blood group influences the severity of their symptoms after SARS-Cov-2 infection. On October 14, 2020, two studies with the same type of results were published in Blood Advances.

According to this work, people in group O are less likely to be infected with the virus. They would also be less likely to develop severe symptoms of Covid-19.

To reach these conclusions, the researchers compared Danish health data collected from 473,000 people who tested positive for Covid-19 to a control group of 2.2 million people from the general population. Among the group of infected persons, a smaller proportion of individuals of group O and more individuals of group A, B and AB were observed. Results that suggest that the blood type influences the level of vulnerability to infection with SARS-CoV-2. However, no significant difference was detected between groups A, B and AB.

More organ failures in groups A and AB?

The second study published on October 14 concerns the degree of severity of Covid-19. The authors reviewed data from 95 patients with the disease hospitalized in Vancouver, Canada. They observed that more people in groups A and AB were subjected to mechanical ventilation. This could mean that they have lung damage more often than individuals of other blood groups. Among this sample, more people in groups A and AB required dialysis for kidney failure. This work could therefore also mean that people of these blood types are more likely to suffer from organ failure than others.

In contrast, among the sample of people hospitalized in Vancouver, patients in groups A and AB were not found more frequently, suggesting that blood type has no effect on the propensity to be hospitalized after contracting Covid-19. However, the study showed that the length of hospital stay was longer for patients in groups A and AB. Another potential indicator of greater vulnerability in these blood groups than others. The researchers want to consolidate their results by comparing them to larger samples and extend their parameters to failures of other vital organs than the lungs and kidneys.

The two studies compiled therefore seem to indicate that the blood group O appears to be more protective on the one hand against infection with the virus, and against severe forms of the disease, on the other hand.

In June, a study by the US biotech company 23andMe found a similar hypothesis. According to this work, individuals in group O have between 9 and 18% less chance of being tested positive for the disease.