If the parents of the child, who is a ward of court and known only as Baby CP, do not present her at a local hospital today, police and social workers can remove her from them.
At the hospital the baby will be subjected to a blood test which will decide if she needs another injection, despite independent medical advice that this is unnecessary, and her parents' continued objection.
The action by health officials in Northern Ireland contravenes current Government policy on immunisation which says parental consent must be given. However, a leading medical ethicist is warning that this is yet another step towards the introduction of compulsory childhood vaccination in the UK. Another senior doctor says the case will do "incredible damage" to the sensitive issue of vaccination of young children.
Baby CP's father said last night: "They have violated our right and duty to decide what is best for our child. We have suffered intimidation and stress and have been put under duress. They assaulted our new- born baby. What they have done, I believe, is illegal."
His wife, an Asiatic woman, carries the Hepatitis B virus. When she became pregnant in 1993, she and her husband, a scientist with extensive medical knowledge, accepted advice that the child should be vaccinated within 12 hours of birth, with two booster injections to follow. The boy developed a "devastating" rash, the parents said, with weeping sores which persisted for months. They blamed the vaccine.
When the woman fell pregnant again, the couple said they would prefer the second child not to be vaccinated. Shortly thereafter they received a letter from the Western Health and Social Services Board (WHSSB) in Londonderry threatening court action if they did not give their consent. Within hours of Baby CP's birth she was made a ward of court with a judge who issued an order requiring her to be vaccinated.
Faced with police and social workers who threatened to take the child, and warned that the father would be charged with manslaughter if she developed Hepatitis B, the couple allowed the child to be vaccinated, but their opposition was recorded.
Since then, the child's father has sought opinions of experts around the world to support his case, but says his grounds for opposing vaccination are ignored.
Dr Bill McConnell of the WHSSB said yesterday that transmission of Hepatitis B from mother to child was extremely high, and it is a Government recommendation to offer vaccination at birth.
"This is a unique circumstance and it differs from the normal immunisation because of the serious consequences of disease. Our overall responsibility is to act in the best interest of the child whether or not the parents agreed and that is why we chose to put the decision in front a judge," he said.
Dr McConnell said that one in six children who contract the disease from their mother will develop cancer or cirrhosis of the liver and die before the age of 16. This figure was disputed by a leading virologist yesterday who said it was based on studies in developing countries and irrelevant to the present case.
However, Dr Richard Nicholson, a physician and editor of the Bulletin of Medical Ethics, accused the WHSSB of "serious abuse of the family" and said neither they nor their medical experts have been given the opportunity to put their case in the High Court.
Professor Jangu Banatvala, one of the country's top virologists said he was "gravely concerned" about mandatory vaccination. "This case will do incredible damage to the cause of immunisation. If parents do not want their child to be vaccinated then you cannot make them," he said last night.