A recent study shows that people with type O blood have a lower risk of developing a novel coronavirus that triggers COVID-19 than people with other types of blood.
Researchers have noticed that people with type O blood are less likely to develop a severe illness if they have the virus.
The results are close to the study reported in June, where researchers concluded that people with type A blood were associated with a 45 per cent higher risk of developing a novel coronavirus.
Those researchers studied 1,900 people in Spain and Italy who were seriously ill with COVID-19 and compared their results with 2,000 people who were not sick.
In March, a study out of China suggested that people with type A blood might be more susceptible to getting the virus and people with type O blood might have more protection against the virus.
The reports have some experts worried that people with type A blood might panic or worry and that people with type O blood might let their guard down or get too complacent.
“These results can’t be used to lessen the serious precautions that everyone needs to take, regardless of their blood type,” Dr. Mary Cushman, MSc, a hematologist and professor at the Larner College of Medicine at the University of Vermont, said in March.
“Someone on social media this weekend wondered if the type O people in families should be the ones sent out for shopping, for instance,” Cushman told Healthline. “We definitely don’t want people thinking they can be protected and don’t have to take precautions because they are type O.”
What the March study reported
The March study came out of Wuhan, China, where the first known cases of COVID-19 were discovered.
In the study, scientists looked at the blood types of 2,173 people who had been diagnosed with COVID-19 and compared that with the blood types of the general population in that region.
They found that in the normal population, type A was 31 percent, type B was 24 percent, type AB was 9 percent, and type O was 34 percent.
In those with the virus, type A was 38 percent, type B was 26 percent, type AB was 10 percent, and type O was 25 percent.
The researchers concluded that “blood group A had a significantly higher risk for COVID-19 compared with non-A blood groups. Whereas blood group O had a significantly lower risk for the infectious disease compared with non-A blood groups.”