Today influenza, or flu, remains the second most frequent cause of death from vaccine-preventable disease in the United States. Epidemics of this highly infectious, acute viral illness were reported as early as 1510. The Spanish flu swept the world in 1918 and 1919, killing more than 20 million people, 500,000 of them in the U.S. alone. Unlike the flu today, the Spanish flu mainly killed young adults. This disease single-handedly decreased life expectancy by 10 years.
It is not surprising, then, that the tension was palpable at the CDC in the United States when, in the winter of 1997, a new and deadly strain of flu emerged in Asia. In August 1997, a young boy in Hong Kong died of a strain of flu that previously had infected only birds. By December, 17 people had been identified with the same strain of flu, and six of them had died. Epidemiologists feared that if this new flu were to spread, not just from bird to human, but from human to human, a massive pandemic could follow. Attempts to produce a vaccine failed; the viruses killed the very cells in which scientists tried to grow them. Finally, not sure if the intervention would work, officials in Hong Kong ordered the slaughter and disposal of 1.5 million chickens. No cases of this strain of flu have been identified since then, but there are no guarantees that it will not re-emerge.
The drama of pandemics should not lead us to underestimate the common flu’s destructive power during a typical year. The CDC estimates that, each year on average, the flu causes 110,000 hospitalizations and 20,000 deaths in the U.S. Almost all the deaths are among the elderly and among those persons who have medical conditions, ranging from pregnancy to chronic lung disease, that predispose them to flu-related complications.
We are vulnerable to the flu each year because the virus mutates enough to get past the antibodies that our bodies formed against earlier years’ strains.
This information is excerpted from the book Vaccinating Your Child: Questions and Answers for the Concerned Parent (Peachtree Publishers, Ltd., 2000). The book’s authors are Dr. Sharon G. Humiston, a pediatrician and clinical researcher at the CDC and the University of Rochester, and Cynthia Good, an award-winning journalist and host of the television show “Good for Parents”.