As with many countries around the world, NZ is experiencing the worst measles outbreak in over 20 years. Welcome back to the dark ages. This was predictable, entirely preventable, and the government were warned. If this outbreak is not stamped out by March next year NZ will lose its hard-earned measles elimination status.
There are four reasons for this – in my opinion, and one solution.
Reason #1. Historical poor uptake of MMR vaccine.
This issue mainly affects people in their teens through to around 30 years of age. When measles vaccines were introduced the incidence of the disease declined. This resulted in two things happening. One; fewer people caught measles so never became immune that way. Two, many people did not receive a vaccine against measles therefore did not become immune that way. There is still a large pool of people in our community who are not immune to measles. Also, of note is that prior to early 2000’s there were many breaches in the cold chain storage of vaccines resulting in loss of potency. This is likely to have affected some of these age groups.
Reason #2. Our vaccine coverage has recently dropped.
NZ improved its previously dismal vaccine uptake thanks to the incredible efforts of many people and the implementation of a national electronic register that enabled immunisation records to be checked and vaccines offered to people who still needed them. The target for MMR vaccine is 95% of all infants fully immunised by age two. We need this proportion of our community to be immune to stop measles being transmitted from one person to another. We almost got there in 2014, however today 2-year old coverage has dropped to around 91%. Among Maori it had dropped to around 86% This means there are too many toddlers and young children susceptible and of particular concern the unimmunised people are not evenly dispersed among the rest of the population creating hot-spots for diseases like measles.
To highlight the first two points here is a graph showing the age distribution of cases so far this year. You can see the immunity gaps.
Reason #3. Global resurgence of measles
Measles has been making a come-back all around the world. In many countries this is a direct result of anti-vaccination activities and a consequent rise in vaccine hesitancy. In fact, the World Health Organization declared this problem as one of the 10 greatest threats to public health for 2019. Pretty sobering. This means immunisation rates are plummeting and more people are susceptible to contracting and transmitting measles. It also means there are more people walking off planes and into our communities carrying the measles virus, so we are being challenged with the virus more often. This argument, specific to NZ was also presented in a paper published in 2017 from Massey University. Which brings me to the forth reason.
Reason #4. Anti-vaccine activity and rise of vaccine hesitancy.
Thanks to social media the anti-vaccine lobby have become coordinated, funded, and lawyered up. This has resulted in an explosion of fake academia (bad science funded by anti-vaccine lobby groups), legal cases (supported by fake experts), and the spread of this fake news/misinformation/baloney like an insidious vermin hell bent on the destruction of public health. This reason underlies reasons #2 and # 3.
The only solution to this evolving catastrophe is to plug the gaps in community immunity to measles by vaccinating those who remain susceptible. Yes, I am talking about a targeted mass vaccination campaign. This is a total no brainer.
It would save money
A cost-benefit analysis of a mass measles immunisation campaign in NZ showed that in 2014 the first 187 confirmed and probable cases cost over $1 million dollars due to loss of earnings lost, management of cases, and hospitalisation costs. The study concluded that a targeted mass campaign to be economically beneficial. Given that the hospitalisation rate during this current 2019 outbreak has been around 30-40% rather than the 10-15% seen in previous outbreaks I shudder to think what the costs have been this far. Who is paying for this do you think?
It would save misery
As of today’s writing the current outbreak has had 639 cases and 237 people had been hospitalised, some requiring intensive care treatment. Of the cases 47/639 had been fully vaccinated. Based on the aforementioned 2017 paper on global importations and population risk factors for measles in NZ there are 435,742 susceptible people here, and vaccinating just 104,357 would make a big difference.
Measles virus infection induces an immune amnesia. The virus destroys the hard earned immune memory you have to other infections, maybe last years cold, that terrible dose of flu, maybe that gastro that had you in bed a week…or maybe even that immunity you developed to something truly vile that might kill you next time! Measles appears to replace some of your existing memory T-cells and B-cells with measles memory T-cells (great for measles immunity!) but you are then left vulnerable to a host of other things. So, basically measles makes you weaker. You do recover from this amnesia and protective memory is restored after a couple of years.
It is totally doable
All the systems and processes required to deliver a targeted mass campaign to those that need it are already in place, they just need resourcing and support. Also a really good communication campaign so the everyone one knows what they need to.
What is measles elimination?
Measles elimination status is when there has been an “Absence of endemic measles virus transmission in a defined geographical area (e.g. region or country) for ≥12 months in the presence of a well performing surveillance system.” In that the same strain of virus has continue to be transmitted in the presence of good immunisation coverage and a disease surveillance system. NZ was awarded this badge in 2017. We could loose it over this outbreak if we do not do something really fast.
Not doing anything at the National level is unacceptable.
National level authorities have known for years that these immunity gaps are a problem yet have failed to act, leaving the management to local District Health Boards. This is a problem for all New Zealanders, measles virus doesn’t give a rodents posterior where the boarders are supposed to be.
The government were also warned by the National Verification Committee for Measles and Rubella Elimination that our elimination status was at risk and why. The committee considered that NZs situation could also become a risk for other countries in Pacific Regions. How embarrassing! The NVC made the following recommendations.
A targeted vaccination catch up programme is required, aimed at closing immunity gaps in the population and starting with areas with the highest numbers of unimmunised people, in particular the Auckland region (Waitemata and Counties Manukau especially). This should be supported by a strong communication campaign, and could make use of the heightened level of public awareness and receptivity to prevention messages owing to the outbreak.
The age for the first dose of MMR vaccine should be systematically brought forward to 12 months from 15 months across New Zealand. Note, this has already been brought forward in Auckland.
Steps should be taken to prevent measles spreading to Pacific Island nations from New Zealand, via communications to Pacific Island governments on vaccination requirements.
Measures to ensure that travellers into and out of New Zealand are vaccinated should be considered, including awareness raising of the risks of measles and the need to be vaccinated for measles.
The Ministry’s response has been to remind people to get vaccinated.