While the flu can be very unpredictable, experts say the signs look promising that this year's flu shot can protect us.
If you think you've already had the flu, Dr. Philip Schwarzman said it was probably something else.
"The flu is just getting here. People often confuse influenza with typical viral respiratory infections," Schwarzman said.
Health officials reported the first cases of the flu in the county - three adults and one child. All four patients, who from the San Fernando Valley and West Los Angeles, have recovered.
The symptoms of influenza are fever, cough and or sore throat, and usually makes you feel pretty sick," Schwarzman said.
Three of the infected individuals affected had the H3N2 flu strain, and the other person had the H1N1 strain. Both are covered in this year's flu shot, along with another influenza B strain.
"I'm glad it came out because maybe people will be encouraged to get their immunizations," Schwarzman said.
The fact that the circulating strains match what's in this year's flu shot is always a good sign, but the flu season typically lasts until May, and protection depends on the severity of the season. Historically, the vaccine has about a 60 percent protection rate.
"Everybody over the age of six months should get vaccinated. That's your best defense against the flu," Schwarzman said.
The county will begin offering free flu vaccines next week. Information on the clinics is available at http://publichealth.lacounty.gov/ip/flu/FluLocatorMain.htm.
Health officials particularly urge pregnant women, children under 5, adults over 50, people with chronic medical conditions and people in nursing homes to get vaccinated.