Local schools have sent out warnings to parents that measles may be on its way to the Wānaka district as 19 confirmed measles cases hit Queenstown.
Wānaka’s general vaccination rate for six-month-old babies is 78.05 percent, whilst Hāwea’s is 71.15 percent. For 60-month-old children, Wānaka’s vaccination rate is 90.91 percent whilst Hāwea’s is 84 percent. The measles, mumps, rubella (MMR) vaccine is given at 15 months, and four years old.
The opposition to vaccinations has risen in recent years on the back of fake news spread by social media. Professor Ross Lawrenson, professor of population health, University of Waikato Medical Research Centre said it is very difficult to get people to understand the seriousness of the measles situation. "[It’s] Difficult really. Six percent will get pneumonia, some will get inflammation of the brain and one or two in 1000 will die. So far we are lucky to have no deaths. Young babies and the immunocompromised are most at risk."
He continued, "For something like measles, which is highly infectious, a vaccination rate of 95 percent is probably needed to protect those such as infants who are vulnerable. The spread of cases suggests we are at the point where herd immunity in some communities has broken down."
SDHB senior communications advisor Vanessa Barratt said that the herd immunity in SDHB was generally very good due to having one of the highest vaccination rates in NZ, although pockets of low vaccination rates around Wānaka district mean there may be individual cases of measles, or even multiple cases in our community.
Nikki Turner, head of the Immunisation Advisory Centre said there have always been communities that have refused to vaccinate. These are often those who live “alternative” lifestyles, seen in parts of the Coromandel, Raglan, Waiheke Island, Hokitika, and Golden Bay.
“Anti-vaccination sentiment tends to group together, so we can have geographic or social groups of very high rates of decline. They all share the concerns together and create their own little patches and then there is real risk of disease spreading in these groups.”
Professor Michael Baker, Professor of Public Health at the University of Otago, emphasised the role of herd immunity in keeping unvaccinated people safe; "Herd immunity, or population protection, occurs when a sufficiently large proportion of a population are immune to prevent the spread of an infectious disease that is passed between people. Because measles is highly infectious the level of immunity to interrupt spread is high, at around 95 percent. This figure assumes that the immunity is uniformly high, so if there are pockets of lower vaccine coverage (immunity gaps), measles can still spread rapidly in those groups. For a number of reasons, New Zealand has some immunity gaps where measles immunity is significantly lower than 95 percent, notably in teenagers and younger adults. So technically, we have probably never had full herd immunity and the highly infectious measles virus is now finding those immunity gaps."
Both Wānaka and Hāwea are below the 95 percent threshold making the district’s vulnerability to measles, higher than other districts within the SDHB.
The SDHB recommends one MMR vaccination at 15-months-old and one vaccination at four-years-old. Adults who are unsure of their immunity status are encouraged to get vaccinated as soon as possible. It is never too late. Those born between 1970 and 1990 are a focus for current vaccination campaigns because their parents and/or doctor may not have a readily available record of their immunisations. This group tends to travel a lot and have young children, adding to the risk factors.