Whooping cough on rise; vaccine waning over time

Health officials are struggling to control outbreaks while facing limited vaccine supplies.

By Victoria Stagg Elliott, AMNews staff. May 27, 2002.

Public health officials around the world are warning of a global re-emergence of whooping cough. State health officials across the United States are reporting that the incidence peaks that characterize the three- to five-year cycles of whooping cough occurrence get higher every time.

And the disease is on the rise in several European countries, said researchers presenting data at the European Clinical Congress of Clinical Microbiology and Infectious Diseases in Milan last month.

"It's a big problem, and everyone is concerned it's going to become a bigger one," said George A. Pankey, MD, director of infectious disease research at the Ochsner Clinic Foundation in New Orleans.

Reasons for the re-emergence are unclear. Some public health officials suspect that because more physicians and public health workers are looking for whooping cough that more is being found. Scientists theorize that the bacteria may have become more virulent and learned to evade the vaccine, although there is little evidence to support that idea.

Other experts suggest that the highly contagious nature of the pertussis bacteria combined with weaknesses in the vaccine might be to blame. The vaccine's effectiveness wanes over time. Most people are left unprotected within a decade of their last booster.

Arkansas, for example, is in the middle of an outbreak that has already made more than a thousand junior high and high school students sick. Local health officials say nearly all of those children had received the required vaccine series. [...]