More than 500 vaccinations were administered in four hours during an H1N1 flu vaccine clinic held at the Cahuilla Desert Academy in Coachella on Wednesday.

Riverside County health officials had offered youngsters ages 2 to 12 who were students of the Coachella Valley Unified School District a chance to receive the nasal spray vaccine.

The clinic was scheduled to run 2 to 6 p.m. but the response was so overwhelming, health officials stayed beyond that time to vaccinate as many children as they could, said Lys Mendez, a Riverside County spokeswoman.

Health officials had originally taken several hundreds doses of the nasal spray vaccine but had called for more to be delivered to the school a couple hours into the clinic to ensure there would be enough, said Michael Osur, deputy director of public health.

Vaccinations started officially at 2:30 p.m., health officials said. Within 21/2

Wednesday's clinic was the only school-based vaccination site scheduled in the Coachella Valley, health officials said.