Dr. George Han with the Santa Clara County Public Health Department spoke with ABC7 News on Wednesday. He expressed sorrow for the family and stressed the importance of getting a flu shot.
In this case, the victim in Santa Clara County had a pre-existing medical condition that put them at risk, such as asthma, diabetes, heart and lung disease, or a weakened immune system.
Han says it's too soon to tell if this early death means this flu season will be more dangerous than last year's.
"It was influenza A," he said. "Most of the influenza A virus that are circulating so far this year seem to be subtype H3N2, and this subtype is actually included in this year's flu vaccine."
Last year there were 78 flu-associated deaths reported in persons under 65 years of age in California.
"As California's public health officer, I am troubled when the flu turns into loss of life. It doesn't have to. That's why I urge you to get your flu shot. By getting vaccinated, you can keep yourself healthy and stop the virus from spreading to others," said California Department of Public Health (CDPH) State Public Health Officer Dr. Karen Smith.
VIDEO: This is what happens when you sneeze on a plane
Overall influenza activity in California remains sporadic, but Dr. Smith points out that influenza viruses circulate at their peak levels from December through April.
"Now is a good time to be vaccinated before the flu really spreads widely," said Dr. Smith.
Each year, flu causes millions of illnesses, hundreds of thousands of hospitalizations and thousands or sometimes tens of thousands of deaths in the United States. To reduce this threat, CDPH recommends the annual flu vaccine for everyone six months of age and older, including pregnant women.
Two of this season's vaccine components, the influenza A (H3N2) and influenza B (Yamagata lineage) strains, have been updated to match the viruses Californians are likely to face during the 2015-2016 flu season.
VIDEO: Watch girl who really doesn't like getting a flu shot
Flu can cause severe disease across all ages. According to the California influenza surveillance report recently published, there were 78 influenza-associated deaths reported in persons under 65 years of age in California during the 2014-15 influenza season. Only deaths in persons under age 65 are reported to CDPH and many influenza-associated deaths are unrecognized. Therefore, the actual number of deaths due to influenza was much greater.
Common symptoms of the flu include fever or feeling feverish, a cough and/or sore throat, a runny or stuffy nose, chills, fatigue and body aches. Children may also have nausea, vomiting or diarrhea.
To stop the spread of flu and other respiratory illnesses, Californians should also:
ABC7 News reporter Natasha Zouves contributed to this report.