Breaking news from the 51st ICAAC meeting in Chicago: Physicians from the Kaiser Permanente Medical Center in San Rafael, California say they have found an unexpected amount of pertussis — whooping cough — in pre-teen children who had received their mandatory school-entry vaccination booster at age 5 and should have been protected from the disease until about the time of their final childhood booster dose at age 12.
The physicians said case records suggest the vaccine may have protected children for less time than it was expected to. They speculate that the cases they recorded — along with additional cases that are likely to have occurred outside Kaiser’s patient population — helped amplify California’s 9,000-person pertussis epidemic in 2010.
“The vast majority of these were fully-vaccinated children,” Dr. David Witt, the medical center’s chief of infectious diseases, said in a press briefing during the meeting. “That was the surprise.”