Is type O blood related to COVID-19?

Does Blood Type Influence COVID-19 Risk?

Since the start of the pandemic, scientists have explored whether certain blood types might affect a person’s susceptibility to COVID-19. Emerging research suggests that blood type—particularly type O—may play a subtle but notable role.

Studies have shown that individuals with type O blood tend to have higher levels of natural anti-A and anti-B antibodies. These antibodies are part of our innate immune defenses and are present without prior exposure to the virus. Interestingly, these same antibodies appear to interfere with the SARS-CoV-2 virus’s ability to attach to cells, potentially reducing infection risk.

One key finding, confirmed in analyses as recent as August 2023, indicates that people with type O blood—who naturally produce both anti-A and anti-B antibodies—had a lower risk of contracting COVID-19 compared to those with other blood types. The same protective effect was observed, though less broadly, in people with type B (who have anti-A antibodies) and type A (who have anti-B antibodies).

While the protective effect isn’t absolute—no one is immune based on blood type alone—it adds to the growing understanding of how biological factors influence viral susceptibility. It’s also a reminder that our immune systems are shaped by more than just vaccines and prior infections; even our basic blood group contributes to the complex shield against disease.

Still, experts emphasize that blood type is just one small piece of the puzzle. Protective behaviors—like vaccination, good hygiene, and ventilation—remain far more impactful in preventing infection. But the link between type O blood and reduced risk offers a fascinating glimpse into how our biology quietly shapes our health outcomes.