The Ventura County Health Care Agency says up to 23,000 patients who received various vaccinations through their ambulatory care clinics might have received less than effective vaccine due to a change in the packaging process for delivering those vaccines to the clinics.
This would cover the period between October 2017 and November 2018 and involve all types of vaccines including flu vaccinations.
The problem is that the new packaging system designed to keep the vaccine in a cool, controlled environment might have kept the vaccines at a cooler than the recommended temperature.
Affected patients will be notified directly and the Public Health Department will be setting up a system to allow patients to get re-vaccinated at no charge.
They say the best course is to get re-vaccinated even if you're not sure the vaccine you or your children might have received was ineffective.
Health officials say getting re-vaccinated is safe.
Patients who might have received the vaccinations in question started receiving notices in the mail this week.
Clinic hours have been expanded and additional clinics will be held to serve those people.
For patients who might have questions, you can call (805) 652-7660 Monday through Friday from 8 AM to 8 PM.
You can also go to www.vchca.org/vaccinesupport for more information and updates.