A North Carolina school known as a place for anti-vaxxers is dealing with a huge outbreak of chicken pox.

More than 2/3rds of the student body at The Asheville Waldorf School have not been vaccinated due to religious exemptions. Now the school is dealing with a chicken pox outbreak that has infected almost 1 in 4 students.

It’s the biggest outbreak in NC in 20 years. Local health officials stressed that vaccination is the best way to prevent chicken pox, and that the vaccine is 90 percent effective.

Source: http://time.com/5460215/chickenbox-outbreak-north-carolina/