Research on a group of Irish women given a contaminated batch of the "Anti-D" product in the 70s, could pave the way for a Zika virus vaccine.
The batch caused serious long-term health problems for hundreds of women.
However, scientists at Trinity College in Dublin want to look at the group of women who did not get sick, despite the product being infected by Hepatitis C.
Trinity's Professor Cliona O'Farrelly hopes they will volunteer for the study.
"We think that they have a particularly super-dooper immune system which we think managed to keep away the virus," she said.
"And we've managed to study a small number of these women and have got some idea of how this immune system works, but we need a much larger study to really confirm that."