COVID-19 and Blood Type
Written by Ada’s Medical Knowledge Team
- Some studies report that people with blood type A may be more susceptible to COVID
- People with type O and Rh-negative blood might have blood antibodies that protect them from more severe symptoms
- A blood protein more often found in A and B blood types might be responsible for some of the more serious COVID complications
- Blood type is only one factor that scientists and healthcare professionals believe can impact the severity of COVID. Other factors include age and pre-existing conditions.
Blood type and COVID-19 symptoms could be connected, as studies suggest that your blood type can be a risk factor for a severe COVID-19 infection. Within your blood group, your blood type and your Rhesus (Rh) factor may affect your chances of getting seriously ill due to the coronavirus. In this article, we explain why this could be the case and how it could affect you.
Why are COVID-19 and blood type discussed?
The relationship between COVID and blood type has been researched to find possible risk factors that may impact the severity and outcome of a COVID-19 infection. As the course of the disease varies amongst patients, it’s important to know which factors may lead to severe COVID. Other risk factors such as obesity, high blood pressure, smoking, age, and underlying conditions have already been determined, but the impact of blood type needs further research. 1
To understand the impact your blood group may have on your resistance against the coronavirus, it’s important to know that there are 4 types of blood: A, B, AB, and O. Each of these blood types can be Rh positive or negative. Your blood type is determined by your genetics and is defined by certain antibodies and antigens in your blood. Antibodies are an important part of your immune system as they defend you against foreign substances. Antigens are substances that your immune system reacts to. 2
Your blood type can be a risk factor for some diseases, such as thromboembolisms (blood vessel obstruction due to a blood clot), certain cancers, and infectious diseases. This is because some of the antigens tied to your blood type can be a receptor for pathogens, organisms that can cause diseases. Besides that, these antigens can also facilitate the uptake of viral particles in the blood. As this has already been proven to be the case for other viruses, bacteria, and parasites, scientists are investigating whether this is also the case for the coronavirus.
Previous research has found that people with blood type O are generally more disease resistant, except for Helicobacter pylori, a gastrointestinal infection ref6, and cholera ref7. People with A, B and AB blood types are more susceptible to other infections, cancer, and cardiovascular diseases. 1
What observations have been made in terms of blood type and COVID-19?
Because of the existing link between blood types and other diseases, the COVID-19 pandemic pushed scientists to research if there was a similar link between blood type and COVID-19, especially regarding susceptibility and severity.
To date, the relationship between COVID and blood type is still not well established. Several studies suggest that people with blood type O and people who are Rh-negative have less chance of testing positive for COVID-19. These studies indicate that these individuals also have less severe symptoms if they do get infected with the coronavirus. 3 4
It’s thought that people with blood group A, B or AB are at higher risk of getting infected with COVID-19 and also have an increased risk for severe symptoms and death compared to those who have blood type O. People with blood type A are thought to have the highest risk of getting infected with COVID-19 and of developing severe symptoms.
What do scientists say about the correlation?
Scientists believe that part of the correlation between blood type and COVID is how well your blood type helps you fight off inflammation and infection. As mentioned earlier, type O has been linked to being more disease resistant. Another interesting component has to do with a glycoprotein called von Willebrand factor (vWF), which is in charge of repairing damage to blood vessels by prompting your blood to clot.
When the COVID virus damages the lining of your blood vessels, the body releases vWF so your blood can fix the damage to the vessel walls. But in the process, your blood is more likely to clot, which can cause other serious complications seen in patients with COVID, such as strokes, kidney failure, and pulmonary embolisms. Research has found that people with type A blood have higher levels of vWF naturally than people with type O blood. 5 6
Even though the correlation between COVID-19 and blood type is not clear yet, several studies suggest that people with blood type O and a negative Rh factor have a lower risk of getting infected with the coronavirus and also have a lower risk of developing serious symptoms, which may lead to hospitalization and even death.
With that said, COVID is a complex condition, and blood type is only one factor that plays into the severity of your symptoms. Other risk factors, including your underlying health issues and age, also play a role in developing complications related to COVID. Of course, if you have type A or B blood, it might be another good reason to stay mindful of good hygiene and keep up to date on vaccinations.
Q: What blood type makes COVID-19 worse?
A: Although the correlation between blood type and COVID-19 is still being investigated, several studies suggest that people with blood type A have the highest risk of serious illness due to the coronavirus.
Q: Am I protected against COVID-19 if I have blood type O?
A: Even though studies suggest that people with blood type O have a lower risk of severe symptoms with a COVID-19 infection, O-positive or negative blood type doesn’t provide COVID-19 immunity.
Q: What blood type is least likely to get COVID-19?
A: Some research suggests that because type O blood contains antibodies that make it more disease resistant than other blood types, it may also make people with type O less likely to contract COVID-19.
Q: What blood type is immune to COVID-19?
A: No blood type is immune to COVID-19.
Q: Which blood group is most resistant to diseases?
A: Previous research has found that people with blood type O are generally more disease resistant, except for Helicobacter pylori, a gastrointestinal infection.
Q: Does blood type affect COVID-19 symptoms?
A: There is some evidence that people with type O blood may be less likely to suffer from more severe COVID-19 symptoms.