The idea that blood type might have a say in whether people contract the novel coronavirus or if developing a serious form of the disease was rather catchy. The claim came from a recent study finding, published in the New England Journal of Medicine, and which focused on the relevance of blood types when it comes to susceptibility to contraction.
The study says that people with type O blood are less likely to get the disease; however, the researchers said, they are not completely immune against infection with the virus. Overall, the paper stated people with type O blood have the lowest risk of suffering from a severe form of the disease.
Blood Type and the Risk of Contracting Coronavirus
Numerous outlets reported the story a few weeks ago, including CNN and NBC News. NBC’s website outlined the results as follows: “Overall, the findings indicate that people with type O blood seem to be more protected and that those with type A appear more vulnerable.”
NBC was also thoughtful to refer to this as only an ‘association,’ not causation. In the original paper, the authors mentioned a few limitations to their research, such as the fact that ‘adjustments for all potential sources of bias (e.g., underlying cardiovascular and metabolic factors relevant to COVID-19) could not be performed.’
However, the idea spread around the world, as it was quickly reported by health and science journalists. Now, further studies have demonstrated that these correlations may not be as strong as initially believed.
A large multi-institutional study published by scientists based at the Massachusetts General Hospital showed that ‘there is no reason to believe being a certain ABO blood type will lead to increased disease severity, which we defined as requiring intubation or leading to death.’
Further Research is Always Needed
Another study from Columbia Presbyterian Hospital in New York discovered that having type A blood did not enhance a person’s risk of contracting the disease, and not having type O blood might not slightly decrease one’s risk. Lead author Nicholas Tatonetti said in the paper that ‘the effect is so small that people shouldn’t count on it.’
This is not the first time that an initial enthralling scientific outcome has been changed or overturned by more research; this has happened all the time in nutrition science or drug trials. Assumed links based on small data sets are well-known phenomena, as shown by this classic xkcd cartoon.
Most scientists know this can happen, which is why they encourage further research that either confirms or disproves their first reports. Out best understanding of the truth is always subjected to further polish or probable mayhem, based on new evidence and better techniques of analysis.
So when we read stories about certain drugs or vaccines that are said to definitely work, it’s probably wise to also do our research before we jump into the unknown and choose to believe counterfeit ‘actuality.’ The truth is out there for those who are willing to see. We just need to exercise some good judgment.