Natomas Unified School District will offer a free Tdap shots to incoming seventh graders on Thursday. The state requires the whooping cough booster before students begin seventh grade.

Whooping cough is a contagious disease that can cause violent coughing fits that make it difficult to breathe.

The clinic will be held from 8 a.m. to 10 a.m. and from 4 p.m. to 6 p.m. at the Natomas Unified Education Center, 1901 Arena Blvd. in Sacramento.

The shot also protects against tetanus and diphtheria.

Parents who want an exemption from the Tdap requirement should get a form from the office at their child’s school. The form must be filled out by a pediatrician and returned to the school.