An unvaccinated high school student from Laguna Beach contracted measles and has been quarantined by county health officials.
Measles is a highly infectious disease; symptoms often include fever, rashes, coughing and red, watery eyes.
It's also incredibly contagious too, as it spreads easily by air and direct contact even before a rash appears.
Orange County Health Care Agency spokeswoman Jessica Good says the infected teen may have exposed their classmates to the virus.
"The ill student, who was also unvaccinated, reported no recent travel outside Orange County or exposure to ill people."
The school district sent out an announcement telling parents about the sick student, what the symptoms are and how to quarantine their child if they get sick.
Six other unvaccinated students have been barred from coming to school and were advised to stay home until April 18th.
Deputy Health Officer of the OC Health Care Agency Helene Calvet stresses the need for vaccinations.
"It’s important to understand that, while the MMR (Mumps, Measles, and Rubella) vaccination is safe and highly effective, no vaccine offers 100% protection against infection...receiving two doses of MMR offers the greatest protection available for all children."
In recent years, many parents have decided against vaccinating their children and have been protected by the personal belief exemptions submitted before the start of 2016.
These personal belief exemptions are valid until the child enters seventh grade.
A new state vaccination law, Senate Bill 277, will stop parents from refusing to vaccinate their children.