Women who were exposed to a blood product contaminated with Hepatitis C in the late 1970s are being asked to volunteer for a study being conducted by scientists at Trinity College Dublin.
The researchers wish to establish why it is that some people seem to have a natural protection against the virus, but others do not.
Anti-D is a blood product that is given to women whose blood groups are incompatible with their newborn baby.
It prevents the mother's immune system from attacking the foetus during a second pregnancy.
Between 1977 and 1979, hundreds of Irish women were given Anti-D contaminated with Hepatitis C.
Many became infected with the virus, which gradually destroys the liver.
But it later emerged that nearly half of the women who had contact with the virus did not become infected with Hepatitis C.
Immunologists at Trinity now want to establish how these women were naturally protected from the virus by comparing their genes with those of women who were infected.
They are appealing to women exposed to the contaminated Anti-D in the late 1970s, who were either infected or not infected with Hepatitis C, to volunteer for the research.
The team says it is an easy, non-invasive study which could have a major impact on fighting viruses, and simply involves giving a saliva sample, which can be done from home.
Speaking on RTÉ's News At One, TCD Professor of Comparative Immunology Cliona O'Farrelly said she believes that some of the women who did not contract Hepatitis C may have a special immune system known as the "innate" immune system, which is very effective against viruses.
She asked volunteers who had received the contaminated blood to come forward for the study, saying: "What we are going to do is look at the innate immune genes in their DNA and compare their innate immune genes with the genes of those who contracted the infection and we are confident that we will be able to see important differences in their genes."
To participate call 087-791-3600 or email TCDStudy2016@tcd.ie.