Waxing due to Waning: The FDA has approved an adult whooping cough vaccine. Whooping cough is pertussis, the "P" in the childhood vaccine dTaP. The "a" stands for "acellular." Before 1997, children were vaccinated with a pertussis preparation made from the entire cells of the pertussis bacteria. That vaccine had adverse reactions such as fever, vomiting, and in some cases, seizures. The incidence of these were small, but they caused consternation in parent advocacy groups.

An acellular version was thus adopted - one that was made of what was considered to be the most important bacterial proteins for providing immunity. There was much concern at the time of its adoption that the new vaccine would confer immunity that was of shorter duration than the whole cell version. The concern was waived off by the public health officials responsible for the decision.

Now, eight years after its introduction, we're seeing an increase in cases in teenagers. Those would be the kids who got the DTaP before they went to kindergarten rather than the DTP. Some say this increase is artificial. That we're just getting better at diagnosing it and that we're more aware of it now in older children than we used to be. Could be. But you have to wonder if the switch to the less immunogenic - but safer - vaccine had something to do with it.

In the near future, you can expect to get a whooping cough booster when you get a tetanus shot. For that's what the new vaccine is - tetanus, diphtheria, and pertussis. An adult version of the infant vaccine. No word on how much it will cost.