Friday 22 / November / 2024
Frankfurt: Why do some people not even notice that they have been infected by the novel coronavirus, while others need medical treatment and ventilation and, in the worst case, can die?
The fact that the disease COVID-19 can take such different courses also makes it difficult to find out how many people are actually infected and how many have already built up immunity. The number of unreported cases is correspondingly high.
Focus on the blood type
German and Norwegian researchers have analyzed the different blood types with regards to COVID-19. They have come up with some amazing results, which they published in the New England Journal of Medicine.
The researchers investigated the role that blood type might play in patients with particularly severe forms of the disease.
In the study, the researchers examined 1,610 patients with COVID-19 respiratory failure in Italy and Spain, where the coronavirus hit particularly hard: Milan, Monza, Madrid, San Sebastian and Barcelona. All patients had a particularly bad form of the disease; some did not survive.
Blood type A means highest risk
A first result: People with blood type A seem to be at a particularly high risk of a severe course of COVID-19. In Germany, 43 per cent of the population has this blood type. They might be twice as likely to need an oxygen supply or ventilation in the event of a coronavirus infection as people with blood type 0, which accounts for 41 per cent of the population in Germany.
The latter would seem to be able to consider themselves lucky as things stand: Even though they are not protected against an infection with the virus, the study shows they have the lowest risk of having a severe case of the disease.
People with type 0- (0 negative) blood also play a special role in blood donations: They are considered "universal donors" and can help anyone in need of a blood transfusion.
Blood types B and AB are not as widespread, making up 11 per cent and 5 per cent of the population respectively. The risk of a severe COVID-19 course for such patients could lie somewhere in between that of patients with types 0 or A, according to the study.
Consequences for treatment
The results of the study may help in developing various drug treatments. Researchers have used similar approaches when searching for medication to fight other diseases.
In the case of malaria, for example, scientists have established a link between the disease and different blood types. For example, it is now known that people with blood type 0 very rarely develop severe malaria and are very well-protected against its most severe form.
In the case of other diseases, other blood types protect the human body best. For example, with the plague, people with blood type A show the mildest symptoms.
For a long time, COVID-19 research focused on high-risk patients: those who have certain preexisting conditions and/or have reached a certain age. Smokers also came under scrutiny as a potential high-risk group. Now, researchers are looking at a different piece in the coronavirus jigsaw puzzle.
