A Cautionary Tale
New diseases, social factors challenge the victories of vaccines
Editor’s Note: This story, first published in 2004, has been updated.
Consider the myriad of diseases that once were, but are no longer, scourges in the Western Hemisphere: polio, smallpox, rabies, measles, mumps, rubella, whooping cough, Haemophilus. Within a few generations, these diseases, which used to account for thousands of American deaths each year, have been virtually eradicated from the population.
Attribute that to one of the greatest triumphs in the history of medicine—the use of vaccines to prevent the spread of dangerous disease. Ever since the 18th Century, physicians have known that inoculating patients with extracted, weakened doses of a virus enabled them to develop immunity to deadly outbreaks. From the mid-20th and continuing into the 21st Century, public health officials have initiated a national campaign to ensure that children receive a series of immunizations against specific microbes. The result, in terms of population health, has been phenomenal.
Ironically, vaccines have now become victims of their own success. “The most effective public health strategy of the century is under great duress,” says Kathryn Edwards, M.D., who joined the division of Pediatric Infectious Diseases at Vanderbilt University Medical Center in 1980, and has subsequently worked on the evaluation and application of the Haemophilus influenza, pertussis, pneumococcus, meningococcus, smallpox, and trivalent influenza vaccines. “When we see disease, we understand how important it is to prevent it. But the more successful we are with our vaccines, the more we (eliminate) diseases and people never see them. So they never fear them.”
Because of some reports of bad side effects, a growing number of parents oppose having their children receive standard immunizations, such as the one against whooping cough. Yet without protection, pertussis can kill. Last year, four children died of whooping cough at Vanderbilt Children’s Hospital.
Edwards says, “I really feel like the Maytag Repairman. The better we are at preventing diseases, the more people are going to say these vaccines are bad. You can design an incredible vaccine, you can test it and know that it works beautifully and it’s safe, but unless you get it into the arms of kids, it’s a failure. So in this field you really have to think more programmatically, more practically and more about public health.”
Pitfalls in the system of vaccine delivery have never been more apparent than during the recent influenza epidemic of 2003-04, when physicians and patients alike were caught off-guard by an early, startlingly virulent and widespread outbreak of the Fujian-A strain of influenza. Deaths from the virus and from secondary infections rose well above the “epidemic threshold” defined by the U.S. Centers for Disease Control and Prevention (CDC). An alarming number of these deaths occurred in previously healthy children. This was a scenario infectious disease experts have predicted and dreaded for some time.