At least 200 students in three counties had not turned in their certificate of immunization form as of Friday to prove they had received a Tdap shot. The shot is a combination of three vaccines that provide protection against diphtheria, tetanus and pertussis (whooping cough).

Under a 2008 North Carolina law, all incoming sixth graders must get a Tdap booster shot within 30 days of the new school year.

Wednesday was the cutoff.

According to school officials, sixth graders in the state, who had not been vaccinated and who did not have an approved exemption, can no longer attend public school until they provide the proper vaccination certification.

The U.S. Centers for Disease Control and Prevention announced on Sept. 11 there would be a nationwide shortage of the Tdap vaccine until mid-October as a result of a delayed vaccine lot.

The shortage lead the Illinois State Board of Education to send a memo this week to school officials saying the Tdap vaccine shortage would be considered when deciding if a school is in compliance with the required vaccination protocols.