A vaccination needle and bottle
Image: Archi Banal

ScienceMay 17, 2023

The current risk of measles and our concerning vaccination rates, explained

A vaccination needle and bottle
Image: Archi Banal

A recent measles scare in Auckland has prompted a renewed call for people to protect themselves against the disease. 

Experts say it seems as though New Zealand may have dodged a measles shaped bullet (for now) after cases were recently confirmed at an Auckland school. But while a widespread measles outbreak thankfully has not eventuated, the scare has highlighted the country’s declining rates of protection against the disease.

The past few years have been largely dominated by talk of Covid-19 and its vaccine, overshadowing conversations around other potentially deadly illnesses and how to stay safe from them. It’s led some experts to suggest that while we may have got lucky with measles this time, there’s no guarantee it will stay this way. 

So what’s the current state of measles in New Zealand?

Two cases were confirmed at Albany Senior High School earlier this month, however no cases have since been reported and all contacts have safely left quarantine. The people who caught measles have also been able to leave isolation.

Te Whatu Ora’s interim clinical director William Rainger said there were almost 1,000 people exposed, making it a “major contact tracing effort” that was managed efficiently. “Surveillance activity will continue as usual, but the risk is reduced now all non-immune contacts from this exposure have been released safely,” he said.

However, he added: “We cannot let our guard slip. Measles outbreaks are still occurring across the globe, and we will see the virus in Aotearoa again sooner or later… Still not enough people in New Zealand are immunised against measles, which means it could just take a single person with the virus to start an outbreak.” 

Were these recent cases a surprise?

In short, no. Health experts said that New Zealand’s vaccination rates coupled with rising case numbers around the world meant it was only a matter of time before measles popped up in the community. The important thing is making sure our protection levels are as high as they can be.

In a piece for The Conversation last August, concern was raised about New Zealand’s vaccination rates and how that could open the door for a measles outbreak. ”The decline in childhood immunisation resulting in low overall coverage is now putting our tamariki at real risk of preventable disease, especially with national borders open again,” the report stated.

Vaccinologist Helen Petousis-Harris told The Spinoff that there has also been a global rise in measles cases on our doorsteps, so it wasn’t totally surprising to see more crop up in the community. “The amount of measles globally has been rising so there is more outside our border than there was [previously] which increases the chances of it being imported,” she said.

So what are our current vaccination rates?

In short, they’re on the decline. “Immunisation coverage at six months of age has fallen in New Zealand from a high of around 80% in early 2020 to 67% by June 2022, and as low as 45% for Māori,” The Conversation reported last year.

And according to the Ministry of Health, people born between 1989 and 2004 are less likely to have been fully immunised as children. Te Whatu Ora’s William Rainger said a lot of young adults missed out important childhood vaccinations through no fault of their own. “If you think you could have missed out on vaccination it’s never too late to catch up. There are no safety concerns with having an extra dose as well, if you aren’t completely sure if you were vaccinated while growing up,” he said.

What about younger people?

The MMR vaccine is available for very young children as part of the immunisation schedule, at 12 months and 15 months old. It’s free for everyone aged 18 and under in New Zealand, and all adults born after 1969 if they’re eligible for free New Zealand healthcare.

And older people?

Adults born before 1969 are considered immune to measles because “the virus is so infectious, and a measles vaccine was not available in New Zealand until 1969”. This means people born earlier were probably already exposed.

What’s the cause of the decline in vaccination rates?

It’s difficult to pinpoint one precise reason for the decline, but anti-vaccination sentiment bolstered by the Covid-19 pandemic certainly won’t have helped. Petousis-Harris said that this may have resulted in “pockets” of very low coverage. “This will likely affect some communities more than others… it can be quite localised,” she said. “The other contributing factor is the obstacles to accessing the service [is] also something that affects some communities more than others.”

Alison Campbell, a biologist with an interest in vaccines, agreed and said that people who were against the Covid vaccine were also, quite often, anti-vaccinations in general. However, she said that our health experts also have to take some responsibility. “I think that the various health agencies also dropped the ball – there was so much messaging around Covid that other infectious-but-vaccine-preventable diseases got lost in the noise,” she said. “That combined with understandable concerns about potential exposure to Covid while getting those vaccines must have had an impact.”

Campbell said that’s certainly been the case in other countries as well and was a concern raised at the onset of the Covid pandemic in 2020.

Wasn’t there measles here not long ago?

Yes, in 2019. The outbreak was the worst measles epidemic in New Zealand since 1938, with over 2,000 confirmed cases, hundreds hospitalised and two deaths. In the same year, a widespread outbreak in Sāmoa killed 83 people.

So what’s being advised now?

The health ministry is urging everyone to make sure they are up to date with their vaccinations, calling the latest measles scare a wake-up call. 

“The MMR (measles, mumps, rubella) vaccine is free for anyone under 18 years old, and we’re working with hauora providers throughout the motu to make vaccination as easy as possible with pop-up clinics and community events,” Dr Rawiri Jackson, chief medical officer for the Māori Health Authority, said. 

A vaccination drive was launched in Auckland at the start of May, which included pop-up clinics in parts of West and South Auckland. A special clinic has also been opened at Albany Senior High School on May 17.

Have we dodged a bullet?

For now, but that doesn’t mean we’ll always be safe. Petousis-Harris said the story would be very different if measles had made it into a community with very low coverage. “[For example] say Northland or South Auckland where coverage dips [into the] low 30% range, then we could have a very big problem,” she said.

Campbell agreed. “Given that early reports were that full measles-vax coverage at the school was around 80%, I’d say that it does look like we’ve got off lightly. However, given the low vaccination rates in some areas, it may well be just a matter of time before we have an outbreak like the one in 2019.”

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