Diseases that marked the childhoods of older generations of New Zealanders are making a comeback today, despite them now being preventable. Cases of measles have been surging worldwide. Recently, the World Health Organisation reported that an estimated 107,500 people, mostly children under 5, died in 2023 because of the highly-contagious virus.
Here, public health experts are warning that it seems a case of when rather than if we will experience a large measles outbreak. “We’re at very high risk and it’s almost inevitable unless we can do something to raise our immunisation coverage,” says University of Otago epidemiologist Michael Baker. “We’re a popular tourist destination and there are people arriving all the time who are incubating measles and will get sick or become infectious while they are here.”
According to the latest data from Te Whatu Ora, the immunisation coverage for children at age 2 in New Zealand is 74.9% – well short of the 95% needed to maintain elimination of preventable diseases such as measles. Baker believes part of the problem is a mistaken idea these are trivial illnesses.
“Measles can be horrible,” he says. “It kills some children and permanently damages some survivors.
“They can end up in hospital with complications like pneumonia and encephalitis.”
The lowest rates of vaccination tend to be in the most at-risk communities. A 2019 outbreak in New Zealand spread to Samoa, where there were 83 deaths and 1867 hospital admissions, most of them babies and young children.
Measles can be horrible. It kills some children and permanently damages some survivors.
“Measles loves immunity gaps. If it arrives in a more deprived neighbourhood, that’s when you really worry about a large outbreak that may be very hard to contain.”
The Covid-19 pandemic has played a part in declining immunisation rates. Not only did it fuel anti-vaccine sentiments, it also took up a lot of health resources. Baker says the key to improving coverage lies with a catch-up campaign using trusted community leaders and health workers. “We know there is a distinction between overtly anti-vax people, who are quite a small but vocal minority, and vaccine-hesitant people. All of us have some hesitancy about vaccines. It’s an inconvenience that we can find reasons to put off. So the challenge is mainly around making it an easy choice for people to make.”
Measles is covered by two doses of the MMR vaccine, which is recommended at 12 months and 15 months and is free for all children under 18 and adults eligible for free healthcare. People born before 1969 are considered likely to be immune because of earlier exposure to the disease.
WHO director-general Dr Tedros Adhanom Ghebreyesus has said MMR has saved more lives than any other vaccine in the past 50 years. Baker agrees. “MMR is an exceptional vaccine. You’re not necessarily 100% protected for life but pretty close to it. And it’s also highly effective for rubella and mumps. So this is a vaccine where I think both the effectiveness and safety are absolutely certain.”
As well as getting that message into communities, he and other public health experts advocate that anyone travelling overseas be prompted to vaccinate against measles, if they haven’t already, to avoid catching the virus and bringing it back to New Zealand.
Measles affected 10.3 million people worldwide in 2023 and, with more than 200,000 overseas visitors arriving here each month, there will inevitably be some outbreaks. So we also need to be poised for “ring immunisation” – vaccinating anyone who has had contact with a confirmed case.
“Measles has an incubation period of a couple of weeks,” says Baker. “If you can vaccinate contacts rapidly while they’re in that pre-symptomatic phase then you interrupt the virus and they don’t get measles.”
Whooping cough (pertussis) is also on the rise globally and, late last year, an epidemic was declared in New Zealand. A highly-contagious bacterial infection, it can be a severe illness for babies too young to be immunised. Three babies died here in 2023.
Although the vaccine for pertussis isn’t as long-lasting, it is included in the tetanus vaccine given free in childhood and can be boosted at ages 4 and 11. In adults, boosters are recommended at ages 45 and 65.
