WASHINGTON — We got several questions from viewers asking if people with “Type O” blood are less susceptible to getting COVID-19?
Question
“Are people with certain blood types at a lower risk of contracting COVID-19? Specifically, "O" blood types?
Answer
Several studies suggest there were fewer occurrences of people with “O” blood types testing positive for COVID-19. However, it’s not conclusive evidence.
Our Sources
Dr. Amish Adalja, infectious diseases expert from Johns Hopkins University. Dr. Anhita Dua, a vascular surgeon from Massachusetts General Hospital and professor at Harvard Medical School
What We Found:
“There is some preliminary data that shows that certain blood types puts you at lower risk for contracting COVID, or having severe COVID,” Dr. Adalja said.
“There are a number of studies that were done around the world. One was done in France, some in China, of course, the United States here at Massachusetts General Hospital,” Dr. Anahita Dua said.
Dr. Dua worked on the Massachusetts general study. She is about to publish a paper on what she found between her study and those done around the world.
“It's still a 50-50 split,” Dr. Dua said. “There is some data that supports the idea that Type O blood, maybe in some way preventing you from getting the disease.”
The issue is all these studies are retrospective. That means the researchers are just looking at patient information after they have contracted coronavirus. They are not conducting a study
“It's not something that you can make a causal link from,” Dr. Adalja said. “Sure, you can get a hypothesis, you can see a correlation and association. But, in science, we want to kind of demonstrate cause effect relationships.”
“So you don't really know, ‘Was it really the blood type?’” Dr. Dua said. “'Or was it something else that was a variable that caused your outcome to be a particular way?'”
Therefore, “currently, blood type is not a part of any decision-making process, whether it be for [the] severity of COVID, or for [the] susceptibility of COVID,” Dr. Dua said.
There is some data regarding blood types. However, at this point experts cannot definitively say people with Type O blood are less susceptible to COVID-19.