Penn State University has confirmed three cases of chicken pox on its main campus in State College.

Students and staff who were in Mifflin Hall between Feb. 17 and 24 or in the Thomas Building on Feb. 20 between 1 and 3 p.m. may have been exposed, the university said in a recent statement. Penn State is also working to notify close contacts of the infected individuals.

Chicken pox spreads through airborne particles and direct contact with an infected person.

Symptoms typically develop 10 to 21 days after exposure, and can include the tell-tale spotted rash, fatigue, headaches and a fever lasting several days. Rarely, the disease can lead to serious complications, like infected blisters, pneumonia, bleeding disorders and brain swelling.

Vaccination significantly reduces infection risk.

The university is encouraging people to check their immunization records, avoid contact with those who are sick and wash their hands often.