Dozens of children have come down with chickenpox at a US school with one of the highest exemption rates in the state.
Thirty-six students at Asheville Waldorf School in Asheville, North Carolina, have contracted the varicella virus responsible for the infectious and painful disease, local newspaper the Asheville Citizen-Times reported.
It's reportedly the biggest outbreak in the state since the vaccine became available in the mid-1990s.
More than 70 percent the private school's children have an exemption to at least one standard vaccine, the chickenpox vaccine the most common, NPR reported.
The usual reason given is religious opposition, but some just don't think vaccines are worth bothering with.
"What's the big deal with chickenpox? There is no big deal," local Amy Gordon told the Citizen-Times. "If I was a parent with a kid who wasn't vaccinated, I'd want to send my kid to the Waldorf School to get chickenpox."
Health officials say this is a bad idea. While often mild, chickenpox causes around 100 deaths a year in the US, according to the Centers for Disease Control.
And those who can't be vaccinated for genuine health reasons, or whose health is more at risk from diseases like chickenpox - such as pregnant women or chemo patients - rely on others to be vaccinated so they don't spread the virus. This is known as herd immunity.
"The thing people need to understand is that when you have pockets of unvaccinated people, they serve as reservoirs for disease," nurse Susan Sullivan told the paper. "It's not just about you."
The school said it follows all immunisation regulations, and that it's ultimately up to parents to decide.
Once infected, the virus doesn't leave a person's body, and can come back as shingles. Possible complications include pneumonia, bacterial infection and inflammation, and if caught by a pregnant woman, is often fatal to the foetus, according to the NZ Immunisation Advisory Centre.
In New Zealand, children receive the vaccine when they're 15 months old. A follow-up shingles vaccine is available when people turn 65. Adult vaccinations are also funded for at-risk groups.