Generations of Maori children and state wards were vaccinated without their parents' consent in baby-boomer inoculation programmes against typhoid and polio.

The policy continued even after the Cabinet became concerned that public health officials administering the vaccines might be vulnerable to assault complaints.

Their reaction was to secretly indemnify the nurses and doctors against legal claims from parents.

The Ministry of Health said yesterday that it did not know when the indemnity ended but said it had certainly been overtaken by legislation respecting patients' rights.

The policy has been revealed in a Herald investigation into the defeat of polio and other deadly diseases in the 1950s and 1960s.

Doctors at Auckland Hospital used stillborn foetuses in their research of the polio virus as they fought to understand a disease that was paralysing children, closing schools and forcing travel bans.

In research that would be controversial today, doctors used human foetuses and monkey kidneys in laboratory studies to find prevalent strains of the polio virus.

In the late 1950s and early 1960s, doctors switched their attention to new vaccines and attacked the diseases with spectacular success.

But policies that underpinned the success of the vaccination programmes included practices that modern-day health authorities would not get away with.

Documents held in the National Archives show child welfare officials decided parents of state wards would not have to be asked before a child was vaccinated.

"Immunisation against these diseases is a widely accepted practice and it is considered reasonable to proceed with it," said a 1962 government paper.

Changes were also written in so that if a parent did object, the objection could be over-ridden.

The 2002 Department of Child, Youth and Family handbook states that consent to immunise children in its care should be obtained from guardians.

Other archived documents show Maori children were vaccinated against typhoid for more than 20 years without their parents' consent.

"For an effective coverage, departmental officers have not sought the consent of individual parents ... relying instead on the agreement of tribal elders," said a memo to the Cabinet in March 1950.

"No law cases or accidents in inoculation have occurred but objections from a few parents create uneasiness from time to time." The concern was that the nurse or doctor could be accused of common assault.

The Cabinet approved a recommendation that public servants be legally protected, but decided the policy should be kept secret.

"It need be known only by senior officers in the health and education departments," said the memo. Another memo recommended against legislative changes that would appear to discriminate against Maori.

Health and Disability Commissioner Ron Paterson said this week that he was not surprised health officials had been so paternalistic, but he did not know they had been concerned about legal risks of not having parental consent.

"I'm surprised they would have perceived that as a significant legal risk and it does suggest a greater appreciation of the need to seek consent than I would have thought," he said.

"It is extraordinary to hear about a Cabinet decision to give indemnity but not to publicise the fact that was happening."

Mr Paterson said patients today were guarded by the provisions of informed consent, even in the public health field.

"There's a recognition now that someone who is offering a vaccine should give very full information about potential risks, and that is clearly the process that the ministry is working through now in relation to the meningococcal vaccine."

The director of public health, Dr Colin Tukuitonga, said officials were carefully following ethical and legal guidelines in the introduction of the meningococcal vaccine, which is being tested in Auckland.

Society's attitudes had certainly changed since the postwar years, when there was a belief the state knew best. "For [Maori and state wards] perhaps the attitude might have been either they don't know or the state is doing something in their best interest," said Dr Tukuitonga.

"It's akin to the removal of Aboriginal children in Australia."

* eugene_bingham@nzherald.co.nz