Your genes may affect your susceptibility to Covid-19

Genetic differences might account for why some people become severely ill with Covid-19, yet others hardly develop a fever or a cough. Or why others lose their appetite and sense of taste or smell, while the unlucky minority suffer flooded lungs.

A new, preliminary study, published April 17th 2020 in the Journal of Virology, throws light on these differences. It may also explain why people with Asian heritage seem to be disproportionately seriously affected, and why men are at greater risk.

Your immune system reacts to a new virus thanks, partly, to specific genes that help cells spot unfamiliar and dangerous microbes or viruses as they enter the body.

Specific genes spot dangerous pathogens

The genes, known as HLA genes, contain instructions that build different types of protein which bind to pathogens, in this case a virus.  The HLA proteins act as a ‘flag’ – signalling to immune cells that the virus is dangerous. This in turn triggers the process of building antibodies to target and destroy the virus. 

But some HLA proteins bind better to the virus than others – and therefore create a stronger immune response – say the researchers based at the Oregon Health and Science University.

If we can identify the genes that produce the weaker immune response, it could lead to identifying people at greater risk of severe reactions. They could then be prioritised for vaccination. It’s an approach that consumer genomics companies are also studying.

Stephen Chapman is at the University of Oxford’s Wellcome Trust Centre for Human Genetics. He is on record as suspecting that rare DNA mutations involved in either immune function or inflammatory responses could be why some young, apparently fit, adults with no other risk factors have been hospitalised in ICU beds. 

Meanwhile, whatever your genetic make-up, there are things that can help support the immune health at this time – see