The latest CDC report shows the flu is now widespread in 41 states. In Southern California, it has already been deadly, and health officials say it's only accelerating.
Kaiser Dr. Stanley Shapiro, who specializes in infectious diseases, says flu season is just beginning.
"There's been a dramatic uptick in the number of positive respiratory samples," he said.
An influenza B-related disease claimed the life of a 51-year-old Fountain Valley man just last week. There were two pediatric deaths reported this week nationwide.
Health officials say it should be reminder to get the flu vaccine, which can come in shot form or as a mist you can inhale. Doctors say it is effective and safe.
"Given the fact that the vaccine matches up so nicely with the circulating strains, and we don't have a lot of variant strains ... I think we may be in good shape as far as the protection provided by the vaccine," Shapiro said.
Doctors say it is most critical for young children, the elderly, pregnant women and anyone with a compromised immune system. But that doesn't mean you should discount the vaccine just because you are healthy.
The vaccine protects against two strains of influenza A and one strain of influenza B. Doctors say equally important is making sure you wash your hands frequently.