The last case of Smallpox occurred in Somalia 40 years ago this month. There were two varieties of the disease, Variola Major, which had a mortality rate of 30 to 35 percent, although children died in much greater numbers, and Variola Minor, which killed about one percent of those infected. Those who survived often suffered from blindness and, of course, pitiful scarring. In the 20th Century, between 300 and 500 million died from the disease.
Smallpox was perhaps the first weapon of mass destruction. After it was introduced by the Spanish in the New World in the early years of the 16th Century, 80 to 90 percent of the native populations infected died of the disease.
Edward Jenner found in 1796 that exposure to the milder disease Cowpox created an immunity to Smallpox. Through the efforts of generations of physicians, Smallpox became the first disease to be fully eradicated, although both Russia and the US have samples of the virus in storage. Our vials are kept at the CDC, a short distance from my home.
Jonas Salk used an inactive form of the Polio virus to create a vaccine in 1955, a year after I was born. Having seen firsthand the devastating paralysis it could cause, my parents did not hesitate to have me inoculated. Today, the disease is nearing eradication, with only 37 cases worldwide reported last year.
Other vaccines followed Salk’s work with general success. The diseases of Measles, Mumps, Rubella, Chickenpox, Diphtheria, and Hepatitis A and B were each reduced and, in some cases, nearly eliminated through vaccines. Pertussis, or Whooping Cough, seems to be coming back, perhaps because the immunity from weaker versions of its vaccine may wear off over time, a situation that occurred in my own case, just a few years ago.
The November issue of National Geographic has an excellent graphic illustrating the impact of vaccines on there diseases. One interesting observation depicted there is the impact of “herd immunity.” 100 percent immunization is not necessary in order to reduce a disease’s incidence to near zero. The greater the percentage inoculated, the less likely it is that any one sick person will infect others.
The concept of herd immunity means that the occasional child that slips through the inoculation net is unlikely to cause great harm to others. This safety net fails, however, when the number not inoculated rises. In 2014 383 measles case arose around an Amish community that had not been vaccinated. Mumps still surfaces today in the US in areas, such as colleges, where unvaccinated may be in close quarters.
All that is why the misguided parents who refuse inoculations for their children based on fake science are a danger. They put not just their own children at risk, but all those that their children come in contact with.
In 1918, 99 years ago, the flu pandemic that circled the world killed between 50 and 100 million people, 10 to 20 percent of those infected. Almost 500,000 Americans died from the disease, reducing the life expectancy in the US by 12 years because of its effects. Today, most of us dutifully find a source this time each year to get our flu shot for the expected strain to impact our population.
Fake news is too easily spread today and is fittingly described as “viral.” The consequences of sharing misinformation can be as devastating as the diseases that good science and generations of doctors have worked so hard to protect us from.
Neil deGrasse Tyson wrote, “The good thing about science is that it is true whether or not you believe in it.” What you say to others, however, could cause lasting harm. Words are powerful tools. Use them wisely.