Canterbury health authorities are having to rejig priorities for the measles vaccine after getting fewer doses than they had hoped for.
It comes as the number of confirmed cases in the district is now 28, while Auckland authorities say there are two new cases in that area.
Canterbury's primary response group had hoped to vaccinate 100,000 people over the coming weeks with the MMR vaccine to control the spread.
Today, a GP leader and spokesman for the group, Phil Schroeder, said they heard yesterday they would now receive 27,500 doses of vaccine.
That included 18,000 doses that have arrived and will be distributed to GP practices this afternoon and tomorrow, and about a further 9500 doses are expected next week.
That meant those first in line would now be those aged 12 months to 28 years who have never been vaccinated at all against measles.
Dr Schroder said it was difficult for GPs, who had many people wanting the vaccine, and wanted to do as much as possible.
He said: "It's a very difficult pill for us to swallow when ... we've been fielding so many questions."
The drug-buyer Pharmac said yesterday there were 60,000 doses of the MMR vaccine in the country in total currently, with a similar amount expected to arrive mid next month.
The director-general of health, Ashley Bloomfield, told TVNZ today that vaccine supplies were needed to maintain regular immunisation programmes for children in the rest of the country as well.
Dr Bloomfield said: "In a typical year we would be vaccinating 144,000 so we would be delivering 144,000 doses.
"Now we have to, on top of maintaining that programme over the next few months, do this vaccination outbreak programme in Canterbury, so that's what we're gearing up for."
Pressed about whether 100,000 people would now receive the vaccine in Canterbury, he added: "We couldn't vaccinate 100,000 people immediately anyway, even if we had the vaccine because there's got to [be] the capacity in general practice to do that. So it was always scheduled to occur over a six-week period. Now that might be six weeks to eight weeks."
Canterbury's Dr Schroeder said of the vaccine supplies: "We've got to work with what we've got. The other [supplies] may have to be deployed into other places in New Zealand by the time it comes in, so we've just got to keep ... we've got to use what we've got and then Ministry [of Health] will come back to us and say ... so it will be a moving feast."
He added the second priority - if extra vaccine was available after those first in line in Canterbury were immunised - would be unvaccinated people up to the age of 50.
"At the moment we've got a guaranteed 27,000 vaccines to administer, and that might increase by another 10,000 or thereabouts in a week or two's time but at this stage that can't be totally guaranteed," Dr Schroeder said.
New cases in Auckland
Meanwhile, Auckland public health authorities said they'd been notified of two cases of measles, and people who may have been exposed should be alert for symptoms appearing.
An adult who contracted the disease was at at the Life Central Church in Normanby Road, Mt Eden, in the evening of Wednesday 6 March.
A child who has also contracted measles was at the Wesley market last Friday morning.
Authorities said Auckland had its first case of measles this year 10 days ago.
The two cases are not linked, nor are they thought to be linked to the Canterbury outbreak.
Canterbury medical officer of health Dr Ramon Pink said they had been monitoring the situation through contact with other health boards.
"I understand that the cases in Auckland are not linked and it's a reminder that measles is not endemic in New Zealand," he said.
"Travellers coming into New Zealand either visiting or returning are the source of measles infection. So, it's likely that that's what's happened in Auckland."
The Northland DHB said it was "only a matter of time" before measles arrived in Northland.
Its medical officer of health Jose Ortega said measles was "a serious, highly infectious, potentially life-threatening disease, and immunisation is the only sure way to avoid getting measles".
- Measles is a highly infectious viral illness spread by contact with respiratory secretions through coughing and sneezing.
- People are infectious from five days before the onset of the rash to five days after the rash starts.
- Infected persons should stay in isolation - staying home from school or work - during this time.
- The best protection from measles is to have two MMR vaccinations. MMR is available from your family practice and is free to eligible persons.
- People are considered immune if they have received two doses of MMR vaccine, have had a measles illness previously, or were born before 1969.
- Anyone believing they have been exposed to measles or exhibiting symptoms, should not go to the ED or after hours' clinic or general practitioner. Instead, call the GP first.