Officials are warning of more measles cases in New Zealand as the spread of the highly infectious disease kills thousands overseas.
Seven people have caught measles in the latest outbreak in Canterbury, and experts say the rise of misinformation online could be one reason for the trend.
It's a disease that's preventable, highly contagious and kills mostly children.
The United Nation (UN)'s Stephane Dujarric said UNICEF has warned that the global cases of measles are surging at alarmingly high levels.
Centres for Disease Control and Prevention's Nancy Messonnier adds the surge is frightening because somebody can transmit measles four days before they have the rash.
"That means they can transmit it even before they know that they're infectious."
A pre-schooler and a woman in her 40s are the latest to contract the disease in Canterbury, which is having one of three small outbreaks in New Zealand in recent weeks.
"We're expecting that there will be more of these small outbreaks, and hopefully not larger outbreaks, within New Zealand this year," the Ministry of Health's Harriette Carr said.
I think it's extraordinary that social media is allowed to just perpetuate stuff that is just straight nonsense and anti-science- Nikki Turner of the University of Auckland
Globally last year there were 50 per cent more deaths because of the disease, claiming the lives of 136,000 people.
Ukraine saw the biggest increase in cases, with 30,000 more than the previous year, with Brazil and the Philippines also experiencing large outbreaks.
And while some of those outbreaks are due to poor health care systems, officials fear a rise of misinformation online is also contributing. In the United States, lawmakers have even asked tech giants such as Facebook to try and manage posts from anti-vaxxers.
Nikki Turner of the University of Auckland says social media should not be allowed to spread misinformation.
"I think it's extraordinary that social media is allowed to just perpetuate stuff that is just straight nonsense and anti-science. We do need some sort of social contract about how we communicate fairly for the sake people and children's programmes," she said.
But experts say the major problem in New Zealand is a fifth of teenagers and young adults not having the full immunisation dosage.
"Immunisation is highly effective. If you have enough of the population vaccinated measles cannot spread," Ms Turner said.
And if you're not sure if you're immunised, the advice is to get a jab anyway.