SALEM — Health officials in Marion County are offering free whooping cough vaccinations in hopes of heading off a pertussis outbreak.

There have been 17 cases of whooping cough reported in the county so far this year, up from just seven for all of 2007.

The vaccines normally cost $15 or $70, depending on insurance coverage. The program is targeted at low-income families with no insurance and those covered by the Oregon Health Plan.

Major complications from prolonged pertussis include pneumonia, seizures, apnea and shortage of oxygen in the body.