The California Department of Public Health (CDPH) last week confirmed the season's first two flu-related deaths in California—one an infant less than six months old. The deaths serve as another somber reminder that influenza can cause serious illness or death.

Influenza viruses circulate at their peak levels from December to April, according to CDPH, which is urging people to get vaccinated before the flu spreads widely.

“As California’s public health officer, I am saddened when the flu turns into loss of life,” said State Public Health Officer Karen Smith, M.D. “It is especially troubling when a baby, too young to be vaccinated, passes away. To protect babies who cannot yet be vaccinated, we should get our flu shots. Preventing the spread of this often deadly disease is why getting vaccinated is so important.”

Young children less than a year of age are at increased risk of severe influenza. While children cannot be vaccinated for the flu until they are six months old, there are several ways to protect them. CDPH also recommends that pregnant women be vaccinated during pregnancy to  help protect both the mother and the newborn baby. Also, vaccinating anyone who is around a young child or other high-risk person helps reduce the risk of spreading influenza.

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 2015-16 flu season. In 2014-15, there were 78 influenza-associated death for persons under 65 years of age in California.