SACRAMENTO (CBS13) — Doctors are sounding the alarm on a whooping cough epidemic in California, as there have been more than 3,400 cases reported statewide in 2014.

“In the last two weeks, there have been more than 800 cases reported to us,” state health department spokeswoman Anita Gore said.

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In less than half a year, California has already topped 2013’s totals. In Sacramento County, cases have more than doubled year-over-year from 74 to 177.

Sacramento County Public Health Officer Dr. Olivia Kasirye says infants are the most at risk, and she encourages pregnant women to get vaccinated in their third trimester to give their newborns some protection.

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“The only way they can get protection is through the mom,” she said.

Doctors say the disease is cyclical, and that it peaks every three to five years. But Kasirye warns of two major concerns: The effectiveness and low usage of the current vaccine.

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“When you look at the immunization rates, especially for school age children, we are seeing a drop in rates.” when said.