The $222 million vaccine campaign against meningococcal disease appears to be sharply reducing the numbers of people hit by the feared illness.

Nearly two years after NZ's largest mass vaccination began in Auckland-Northland, the region has experienced a 76 per cent drop in cases of the strain targeted by the MeNZB vaccine.

Among Maori, the number has declined by 90 per cent when comparing 2003, the year before the campaign started, with 2005, the year after.

In the region, cases of all types of the disease, including strains not covered by the vaccine, declined from 150 in 2003 to 63 in 2005.

The Government is claiming success for the $200 million campaign to vaccinate young people from the age of 6 weeks to 19 years, which was to have ended last Friday.

It has been extended to the end of this year by an extra $22 million, which is also to see it through to 2009 for newborns and preschoolers.

"With the mass-immunisation phase of the campaign coming to an end, there's a lot to be celebrated," said Health Minister Pete Hodgson. "We are seeing more and more evidence that we're beating this epidemic."

The epidemic took off in 1991. Since then, more than 5000 cases, mainly of the epidemic strain, have been reported. It has killed 238 patients, and many others have suffered complications such as brain damage or limb amputations.

Baby Charlotte Cleverley-Bisman became the face of the campaign after contracting the epidemic strain in the month before the mass vaccination started. She went on to have parts of both legs and both arms amputated.

Her family on Waiheke Island publicised her tragic case to encourage people to take advantage of the vaccination once it became available.

Her father, Perry Bisman, last night described Charlotte, now aged 2 years 8 months, as a healthy, happy and determined girl.

She is unable to walk and is expected to need a wheelchair, but she is pulling up on furniture and she skateboards. "She can get her arms and torso on the board. She's able to skateboard around [using] some special soft liners from her artificial legs. She can push along the ground without getting grazed.

"She's a very active child. She gets frustrated when she sees other kids doing things and can't do them."

South Auckland has been one of the areas hardest hit by the epidemic, which has disproportionately affected Maori and Pacific Island babies in poor suburbs. It is there that some of the first children were vaccinated.

Tueila Percival, a paediatrician at KidzFirst, part of Middlemore Hospital, said she had seen a "dramatic decrease" in cases.

"We hardly ever see many cases now. Before, it was several times a week.

"It's wonderful, really. It's a devastating disease. We've all seen cases where kids come in with it. We do everything we can [but] they are dead a few hours later.

"In the Pacific community, almost everybody knows a relative who has had it. People were really looking for answers," said Dr Percival, a Samoan. She said it looked as though the epidemic was beaten.

But the Ministry of Health is more circumspect. Its head of the vaccine strategy, Dr Jane O'Hallahan, said the reduction in cases was dramatic, but there was a way to go yet. "I think we've got to get through another two winters, this one and another one, before we can say it's over."

Sceptics have pointed to the downward trend nationally in cases before the mass vaccination started, but Dr O'Hallahan said that trend was not true of Auckland-Northland, where the 76 per cent reduction occurred after vaccination started.

There had been fluctuations previously in the epidemic, but it had been expected to last for up to another 15 years.