Harvard Medical School researchers explore blood type links to SARS-CoV-2 infection risk
Researchers at Harvard Medical School report that individuals with the second blood type may face a higher risk of SARS-CoV-2 infection. The study appears in the journal Blood and focuses on how the virus interacts with red blood cell surface proteins linked to blood type.
In laboratory experiments, scientists tested blood samples from individuals with blood types A II and O I to observe how SARS-CoV-2 interacts with cells carrying specific blood group markers. Their observations indicate that the virus more readily targets cells associated with the second blood group, suggesting a higher susceptibility in this subgroup under controlled conditions.
The team explains that the increased affinity likely stems from the virus binding more strongly to certain surface proteins present on the cells of the second blood group. When researchers introduced a protein designed to block the virus from recognizing these surface proteins, infection of the second blood group cells decreased, supporting the idea that cell-surface interactions drive entry for SARS-CoV-2 in this context.
Earlier investigations have hinted that individuals with blood type II could be up to 20% more likely to become infected after exposure to SARS-CoV-2 compared with those who have blood type I. While these findings point toward a possible mechanism, this study is among the first to demonstrate a plausible biological route for such a difference, tying cellular entry to blood group–related surface proteins.
Despite the new data, the researchers caution that possessing blood type O does not render a person immune and that all groups should continue to follow public health guidance to reduce infection risk. Precautions such as vaccination, masking where appropriate, ventilation, and hygiene remain important for everyone, regardless of blood type.
In related clinical observations, a neurologist notes that acute intervertebral hernias can improve over time in a majority of cases, with many patients experiencing significant relief of symptoms as natural healing and treatment progress occur.