California is now officially dealing with a whooping cough epidemic.
The state says more than 3,400 cases of pertussis have been reported since the first of the year, including 800 over just the past two weeks.
The total number of cases reported so far this year, more than were reported during all of 2013.
Whooping cough is cyclical, peaking every three to four years.
Infants too young to be immunized are the most vulnerable and two have died since January.
Health officials say all pregnant women should be vaccinated with Tdap in the third trimester of each pregnancy.
Infants can receive their first dose of vaccine as early as six weeks of age.