Anti-vaxxers aren't just a danger to your baby - they're one of the 10 biggest threats the world faces today, according to the World Health Organization (WHO).
The United Nations agency has listed 'vaccine hesitancy' alongside influenza, superbugs and Ebola, saying it "threatens to reverse progress in tackling vaccine-preventable diseases".
"Vaccination is one of the most cost-effective ways of avoiding disease - it currently prevents 2-3 million deaths a year, and a further 1.5 million could be avoided if global coverage of vaccinations improved," the WHO wrote on its website.
"Measles, for example, has seen a 30 percent increase in cases globally. The reasons for this rise are complex, and not all of these cases are due to vaccine hesitancy. However, some countries that were close to eliminating the disease have seen a resurgence."
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The anti-vaccination movement, often referred to as 'anti-vaxxers', got a shot in the arm in 1998 with the publication of a paper linking the MMR (measles, mumps and rubella) vaccine to autism. The paper was later retracted and the author, Andrew Wakefield, struck off the UK medical register for fraud.
But the myth persists. A survey in 2017 found more than a third of US adults believed they knew more about the causes of autism than doctors and scientists. The less a person knew about autism, the more likely they were to think they know better than the experts.
A report by WHO last year directly blamed anti-vaxxers for a rise in measles cases, particularly in wealthy Europe and North America.
About 95 percent coverage is needed for herd immunity, so people who can't get the vaccine - those with weak immune systems, babies and cancer patients for example - are protected.
New Zealand currently has above 90 percent coverage, and outbreaks are usually caused by people arriving from overseas with the disease. Worldwide, coverage for the most common communicable diseases is at 85 percent.
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WHO estimates 21 million lives have been saved since 2000 thanks to the MMR vaccine.
In 2019, it says efforts will ramp up to "eliminate cervical cancer worldwide by increasing coverage of the HPV vaccine, among other interventions".
"2019 may also be the year when transmission of wild poliovirus is stopped in Afghanistan and Pakistan. Last year, less than 30 cases were reported in both countries. WHO and partners are committed to supporting these countries to vaccinate every last child to eradicate this crippling disease for good."