So far, California has only seen sporadic flu activity, but that's expected to change as kids head back to school.
Fresno's Kaiser Permanente Medical Center declared its flu season this week, after the system's Northern California region reported a surge in the number of confirmed cases. But experts stress there's still time to protect yourself and others.
David Luchini with Fresno County Public Health said, "We try to remind people, it's not just about protecting yourself when you get vaccinated. But also the people around you, the family, close friends that may have chronic illnesses or the elderly that are at higher risk of complications from influenza."
Public health officials say there are plenty of vaccines still available, and they take about 10 days to two weeks to take full effect.
If you need one, contact your healthcare provider. They're also offered at a low cost at the county health department Monday through Friday, from 8:00 a.m. to 12:00 p.m. and then 1:00 p.m. to 4:00 p.m.