Randy Ward couldn't have made his message any clearer Wednesday.
The San Diego County Superintendent of Schools said it in English. He repeated it in English. Then he said it in Spanish.
"No proof, no school," Ward said. "I repeat: No proof, no school."
A new law will take effect July 1 requiring all California students grades seven through 12 to provide valid proof of a whooping cough vaccination. Any student who doesn't submit proof can not be legally enrolled.
About 236,000 students in San Diego still need to provide that evidence, and school nursing personnel estimate half of those students have yet to be vaccinated, Ward said.
"We've got a lot of work to do," Ward said.
There were 1,044 whooping cough cases in San Diego last year, including two infant deaths. Statewide, California had 8,300 cases in 2010, its most since 1947.
This year, at last count, there have been 205 cases in San Diego.
Students covered by health insurance can be vaccinated through their primary health care provider. Students without health insurance can call 211 to learn the location of the nearest available public health center.