California health officials say there's a rise in the number of people infected with whooping cough. There have been 77 cases in San Diego County so far this year, compared with 30 at this point in 2009.
Whooping cough is also known as pertussis. It's a highly contagious disease that affects the respiratory system.
Children typically receive five doses of the pertussis vaccine by the time they enter kindergarten. But the vaccine is not 100 percent effective. Three local children who were recently diagnosed with the disease were fully immunized.
Dr. Dean Sidelinger is San Diego County's deputy public health officer.
"What we have seen," Sidelinger says, "is that people who are fully vaccinated who come down with pertussis, may have milder cases of pertussis and may not have more of the serious symptoms than someone who's not vaccinated has."
Sidelinger says infants are especially vulnerable to whooping cough.
