As of Tuesday, Corona del Mar and Newport Harbor high schools had the highest number of students who were not yet compliant, but the numbers districtwide are coming down very quickly, Grasska said.
Whooping cough — the common name for pertussis — caused an epidemic in California last year, with the highest number of cases reported in 95 years.
At least 10 infants died and more than 11,000 people fell ill, causing the state to require students to get the Tdap booster shot to vaccinate them against whooping cough.
Newport-Mesa Unified had one suspected, but unconfirmed, pertussis case last year, Grasska has said.
Grasska wants parents to know that it's important for students to get vaccinated, but those families that won't need to turn in an exception waiver.
"The immunization is in the best interest of the student's health and the student community's health," she said.
Fears about vaccinations, which have largely been disproved by the medical and scientific communities, have led to decreases in vaccinations in some circles nationwide. Orange County health officials have urged parents to continue vaccinating their children.
Parents can get their children vaccinated for free from 4 to 6 p.m. Wednesday and Thursday at the HOPE clinic, 2045 Meyer Place, Building C, Costa Mesa. For more information, call (949) 515-6725.