'There are a million questions you want to ask. One door just opens another. And finally you end up with the most basic question of all - why me?" These are the words of the man known as Baby A, writes Mary Raftery.
He is the only person who so far has had it confirmed to him that he was the subject of an experimental vaccine trial in a mother and baby home in 1960.
"When I was a baby," he told me when we met some weeks ago, "I was just a number, a category. Why are they still making me feel like that?"
The vaccine trials on newborn infants have been the subject of considerable public concern since first exposed over 15 years ago. For a decade, the Government stalled on the issue but finally decided to act.
In a passionate speech to the Seanad in November 2000, the then minister for health Micheál Martin outlined the critical concerns raised by these trials. "The key issue," he said, "that of consent, cannot be fudged because it is fundamental. Children in care have the same rights as other children." He pointed to a number of issues related to the ethical basis of the trials and emphasised that he found the lack of documentation on them both "puzzling" and "unsatisfactory".
In 2001 the Oireachtas passed legislation to direct the Commission on Child Abuse to investigate the issue. This was described by the minister as "the ultimate guarantee against a cover-up or whitewash".
Referring to those who were the subject of the experimental vaccine trials, he said: "We do not know whether your rights were protected all those years ago, we just do not know, but we believe it is important for you and for the wider society to move heaven and earth to find out." However, the commission's inquiry quickly became bogged down in court challenges. When the Supreme Court ruled in 2003 that Prof Patrick Meenan, who had directed Baby A's 1960 trial, did not have to give evidence, the investigation procedure was shelved.
Last summer, it collapsed completely. On application from Prof Irene Hillary, who had conducted a number of the vaccine trials, the court ruled that the Government's order directing the Child Abuse Commission to investigate the vaccine trials was invalid.
When you ask the Department of Health these days how they now intend to pursue the inquiry, what you get is the standard fudge that they are considering the matter - a far cry from "moving heaven and earth" only a few years ago.
Baby A - we will call him Peter - finds all of this intensely frustrating. For the sake of his family and small children, he wants to preserve his privacy. But he feels that unless someone speaks out, "the Government will just let this one quietly die away".
For most of his life, Peter had no reason to think that there was anything unusual about his background. When his mother died 10 years ago, he began to hear rumours locally that he had in fact been adopted. It transpired that the woman he thought of as his aunt was in reality his true mother.
She had been in the Bessboro Mother and Baby Home in Cork, and it was there that four-month-old Peter received the experimental 4 in 1 or Quadrivax vaccine from Prof Hillary in 1960. No evidence has emerged that either he or any of the other babies suffered harm as a result of this.
According to Peter, his birth mother (who now lives abroad) has told the Child Abuse Commission that she neither gave nor was asked to give consent to her baby's participation in this vaccine trial, and that she was told nothing about it.
Peter also had lived abroad for many years, but found himself so upset by the discovery of his involvement in the vaccine experiment that he has returned to Ireland to find the truth.
"It's difficult to explain the effect something like this can have on you," he says. "It has just turned my life upside down. I'm four months old, lying in my cradle, I'm completely vulnerable. I want to know who decided to do this to me and what gave them the right." Peter is one of 58 babies included in the 1960/'61 trial, spread across five mother and baby homes throughout the country.
Other vaccine trials to be investigated involved additional children's homes in the early 1970s.
Before its investigation was shut down, the Commission on Child Abuse anticipated that evidence could emerge of further trials involving children and babies. In total, they considered that up to 300 infants were part of such trials.
As the only one to come forward so far, Peter feels acutely isolated. "The names of the others are there, but no one has bothered to find them. It means I'm the only one fighting to get to the truth here. That makes it even harder when all I feel is that everyone else just wants the whole thing to disappear."