A top immunologist has explained why some people are simply able to avoid catching Covid-19.

As reported by Dublin Live, Dr Cliona O'Farrelly, who is a professor of comparative immunology and biochemistry at Trinity College, spoke on the Claire Byrne TV show about a number of factors that helped people avoid the virus.

She claimed this was due to socio-economic backgrounds, generally good health, careful behaviour and a rare innate immune response.

Dr O'Farrelly added: "How people live has got a lot to do with their circumstances and then on top of that then is this percentage of people who have what we would call an innate immune signature, that's what we're looking for.

Maldon and Burnham Standard: Some people have an innate immunity to the Covid virus (PA)Some people have an innate immunity to the Covid virus (PA)

The innate immune signature that identifies the resistance so I think those four things are really important; your socio-economic status, your general health well-being, how you behave and then this innate resistance."

Dr O'Farrelly has also for several years worked on a study about women who contracted Hepatitis C through blood transplants and why some women did not contract the virus. She believes it is down to the innate immune response similarity with Covid.

Alongside this there is currently a large international consortium studying people from 40 countries who have not become infected from Covid-19 despite being close contacts of the virus.

At the moment, they are seeking people from Ireland who have never had Covid to take part in the large study.

Dr O'Farrelly said: "Ideally we are looking for people who have resisted the virus twice, during the first wave and more recently with the Omicron and ideally we need people whose partner was PCR positive while they shared a room with them and they remained PCR negative."

This study is looking for "genetic markers" of resistance to infection.