Researchers believe the study could help persuade people who are hesitant about getting a COVID vaccine to get their jabs.
Polish scientists have found a gene that they say more than doubles the risk of becoming severely ill with COVID-19, a discovery they hope could help doctors identify people who are most at risk from the disease.
With vaccine hesitancy a major factor behind high coronavirus death rates in central and eastern Europe, researchers hope that identifying those at greatest risk will encourage them to get a shot and give them access to more intensive treatment options in case of an infection.
"After more than a year and a half of work it was possible to identify a gene responsible for a predisposition to becoming seriously ill (with coronavirus)," said Poland's health minister Adam Niedzielski.
"This means that in the future we will be able to... identify people with a predisposition to suffer seriously from COVID".
Other genetic factors
The researchers from the Medical University of Bialystok found that the gene was the fourth most important factor determining how seriously a person suffers from COVID-19, after age, weight, and gender.
The gene is present in around 14 per cent of the Polish population, compared to 8-9 per cent in Europe as a whole and 27 per cent in India, said Marcin Moniuszko, the professor in charge of the project.
Other studies have also shown the importance of genetic factors in how seriously COVID-19 develops.
In November, British scientists said they had identified a version of a gene that may be associated with double the risk of lung failure from COVID-19.