Graphic depiction of a measles virus Photo: THOM LEACH / SCIENCE PHOTO LIBRA /AFP
Health officials have confirmed two more cases of measles - both in Auckland - bringing the number in the current outbreak to 13, with more than 2000 close contacts identified so far.
Together with the 12 cases in the separate Northland outbreak, that makes 25 known measles cases this month.
At a media briefing on Thursday afternoon, national public health service director Dr Nick Chamberlain said one person tested positive for measles on Wednesday and the other on Thursday.
"One was a close contact, so if not expected at least it wasn't a complete surprise. Certainly the second case - at this very early stage because we only heard about it at 10am - we haven't found any known links [to previous cases]."
So far, 2142 close contacts have been identified in the current outbreak, Chamberlain said.
More locations of potential exposure are being published as they are identified and close contacts notified.
Dr Chamberlain said nine or 10 of the cases in the current outbreak had turned out to be linked to the Northland outbreak earlier this month.
How can you check if you have been vaccinated?
If you were born before 1969, you are likely to be immune already because you probably had measles as a child before vaccination became widely available.
But the Health Ministry's director of public health Dr Corina Grey said authorities were "encouraging everyone to check their vaccination status".
"Ask your GP if you have two documented doses of MMR."
More information is also available here or by calling the free Vaccination Helpline on 0800 28 29 26.
Vaccination records from 2005 are "very robust", and anyone vaccinated after that date would have an electronic record, she said.
How can you check if you are immune?
Health NZ is running "pop-up" serology clinics to offer free testing of immunity levels for people who know they have been exposed to an infectious case.
Dr Corina Grey. Photo: Supplied
Grey said one such clinic was hosted on Thursday by Wellington Girls' College, where dozens of students and staff are considered close contacts.
"But we don't advise people getting a test to find out if they have been immunised.
"If you're unsure and you've checked with your doctor, it is safe to get another dose of MMR and those are free - you can get them through pharmacies."
Will Health NZ drop the age for babies to be vaccinated?
Under the National Childhood Immunisation Schedule, the MMR vaccine is given at 12 and 15 months.
The vaccine can be given under prescription to babies as young as four months if they are travelling overseas to countries with measles outbreaks, if they are close contacts or when there is uncontrolled community spread.
Photo: Stuff / Denise Piper
"We acknowledge that for the parents of very young babies, the current outbreak can feel very unsettling," Grey said.
"If you give the MMR to someone under 12 months we call that MMR Zero and that does provide some protection - but the proportion is lower the younger the child is and they still need to get two doses after that."
Furthemore, there was some evidence that "the protection offered over the lifetime of a person may be weakened" if they received a dose before 12 months of age, she said.
"There's a kind of trade-off between protecting someone now and in the future."
Public health authorities were looking at what different countries were doing in regards to Dose Zero, she said.
For instance, Britain decided not to provide Dose Zero during its own significant outbreak, but instead took a "very targeted" approach and offered it to children who were close contacts.
"We are reviewing the evidence, but at this stage we're not offering it to all children."
What is Health NZ doing to prepare?
Nick Chamberlain said the risk of further measles outbreaks was high and had been "high for several years".
"So the current situation is not a surprise and we have been preparing for it."
Since the first case this month, the National Public Health Service had been leading a nationally co-ordinated response, beefing up its contact tracing staff capacity and expanding access to immunisation.
"We have plans in place to cope with about 100 cases a week at the most, which would really stretch our services, but we are seeing an increase of about one a day at the moment."
Whether that trend continued or (as with previous outbreaks) it was successfully "contained", there was no doubt New Zealand would continue to have further outbreaks until it achieved higher immunisation coverage, he said.
There had been a surge in MMR vaccinations in the last week, with 770 more doses given, on top of the average of around 3000.
Many of those are children under two, with 9000 to 10,000 usually vaccinated every week against the range of childhood diseases.
Health authorities are running an immunisation week next week, to boost awareness and accessibility.
"Measles is one of the most contagious diseases on the planet," Chamberlain said.
"If you're exposed to it and you're not immune, there's a 90 percent chance you'll get it, and every infectious person will infect between 12 and 18 non-immune people."
During the last major outbreak in 2019, New Zealand had 2200, with about 700 (about one in three) admitted to hospital.
Public health officials are meeting with primary health organisations and GP leaders in "the next week or so" to discuss strategies for preparing for further cases or future outbreaks.
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
