EL SOBRANTE, Calif. -- A school in Contra Costa County shut it doors Friday following an outbreak of whooping cough among kindergarten students and teachers.

A notice posted on the doors of the East Bay Waldorf School in El Sobrante says the school will be closed for the day because of the outbreak involving kindergarten students and teachers.

Contra Costa County health officials plan to release more information about the school closure during a media briefing Friday morning.

A letter posted at the school said that students would be allowed to return to classes Monday if they had proof of taking antibiotics or vaccine to fight the disease.

Whooping cough -- or pertussis -- is considered highly contagious. Symptoms include a prolonged cough that ends in a whooping sound when the person takes a breath.