In the annual battle against influenza, county public health clinics deliver hundreds of thousands of doses of immunity-building shots each year. This year, some counties are reporting that orders have been delayed.

In Yolo County, Immunization Coordinator Lynne Foster reported that while the county received enough doses for a planned Oct. 3 free public flu clinic, 500 vaccines intended for county employees have been delayed by as much as two weeks.

In Fresno County, Flu Clinic Coordinator Tom Booth is still waiting for 4,000 doses to be delivered from the state. He is not worried, however.

“We have enough to get halfway through flu season,” Both said.

Fresno rural clinics start Oct. 6.

Each year, the formula for the inactivated vaccine is reconfigured based on international data about which strains of viruses will dominate in a given year. Some years this process results in a race to produce enough doses to meet demand before the virus takes hold.

“The vendor is running behind, probably because they are busy making the swine flu virus,” Foster said.

Thomas Skinner, spokesman for the Centers for Disease Control and Prevention (CDC), said a little more than 50 million doses of seasonal vaccine have gone out of the 114 million expected. He did not consider the phased shipments a delay.

“More are on the way,” Skinner said.

The need for both seasonal flu vaccines and swine flu (H1N1) vaccines has confused some patients and tested the health delivery system across the country. Both are required for at-risk groups to protect against the most likely outbreaks.

“This year both the seasonal flu and the H1N1 flu virus will be circulating,” said Dr. Gil Chavez, acting chief deputy director for the California Department of Public Health.

Although swine flu has received the most publicity this year, seasonal flu also packs a punch. Each year, as much as 20 percent of the U.S. population falls ill with an influenza virus. More than 36,000 of those who get sick die from complications.

Dr. Chavez said he expects this year’s flu season to be more severe than normal and encouraged health care workers, children and those over 50 to get both vaccines.

The first 3.4 million doses of nasal swine flu vaccine could ship in early October, according to the CDC. Swine flu shots would follow in weekly waves after that until a total of 195 million doses are delivered nationwide.

Counties will play an important role in prioritizing the shipments. Along with state departments of health, local public health departments will triage orders for retail and healthcare providers and pass that information on to the CDC.

JT Long can be reached at