We are at least eight months into the Covid-19 new pandemic and we are quickly learning about this virus and how it affects our bodies. A few weeks ago there were reports that a person's blood type might protect them from getting the infection. We now know this is not true. But first, a quick tutorial on human blood type.
Each of us inherits our blood type that is carried by an antigen on our red blood cells (RBC). The RBC is the largest quantity of blood cells in our body and is mainly designed to carry oxygen to our tissues. Each of us is either Type A, Type B, Type AB or Type O with a protein that is either positive or negative and is called Rh factor. We know that these types are critical in blood transfusions and receiving the wrong type of blood will cause a severe reaction. Every time a person is administered blood they get a "type and cross" that checks the blood type and makes sure the proper transfusion is given. People with Type O blood have no antigens so they can be given to all blood types and are called the universal donor.
It is nice speculation that a blood type might be Covid protecting but the peer-reviewed data does not show any difference.
Harvard Mass General just reported on an observational study of 1289 Covid positive patients. They ranked them for race, age and co-morbidities and wanted to know if blood type had any effect on the severity of the Covid illness. They looked at admit, ICU admit, intubation and death and found that there was no difference between any of these outcomes and a patient's blood type.
Because we know inflammation plays a role in severity of illness, they also looked at markers of inflammation and blood type and found no difference.
Scientists will continue to learn more about Covid and how it behaves and why certain people have worse outcomes.
For now it's not blood type.