In 1952, the number of polio cases reached nearly 60,000, making it one of the worst epidemics in U.S. history. More than 3,000 people died, and more than 21,000 were left with mild to disabling paralysis.

In early April 1955, Marvin M. Lipman, who has been Consumers Union’s chief medical adviser since 1967, was an intern. While attending a scientific meeting in Atlantic City, N.J., he heard Jonas Salk describe the results of a preliminary study demonstrating the efficacy of his polio vaccine. He still recalls that the thunderous applause lasted at least 10 minutes.

Shortly afterward, on April 12, 10 years to the day after the death of President Franklin D. Roosevelt (himself a polio survivor), a much-anticipated radio broadcast proclaimed Salk’s vaccine safe and effective. As its use became widespread, the number of polio cases quickly began to dwindle, and it has now been eliminated in this country. The last reported case originating in the Western Hemisphere was in Peru in 1991.

Of all the advances in medicine during the course of the last century or two — including anesthesia, antibiotics, sterile surgical techniques, cancer chemotherapy and the prevention of heart attacks and strokes — probably none has had a greater impact on human sickness and death than the widespread use of vaccines.

Smallpox, a scourge that killed millions through the centuries, is now a distant memory; the world’s last case was in 1977 in Somalia.

Vaccines have significantly reduced the number of reported cases of other diseases. Diphtheria and invasive hemophilus influenzae B have been cut by 100 percent in the United States; mumps, by 96 percent; tetanus, 93 percent; whooping cough, 92 percent; hepatitis A, 87 percent; chickenpox, 85 percent; and acute hepatitis B, 80 percent. The decline in cases of pneumococcal pneumonia has been only 34 percent, probably because many elderly or chronically ill adults who need the vaccine don’t get it.

Get your shots

Despite the formidable evidence that vaccines prevent or reduce the severity of many infectious diseases, a substantial but vocal minority of people not only refuse vaccinations for themselves and their children but also advocate against the use of vaccines by others. The reasons vary but basically hinge on the belief that vaccines are harmful. At one point or another, anti-vaccinationists have blamed vaccines for attention-deficit hyperactivity disorder, autism, brain damage and multiple sclerosis.

Many well-designed studies have found that such blame is misplaced. Reactions in the first days after a vaccination can include a sore arm, fever, aches and pains, but these are minor, usually well tolerated and resolve quickly.

A more serious reaction can occur, usually after four or more weeks, but it’s rare. For example, the risk of brain inflammation after a measles vaccination is one in a million. But the risk after natural infection with the measles virus is much greater — one in 1,000 cases. The estimated incidence of Guillain-Barre syndrome, a serious paralytic neurological disorder, after influenza vaccination is about one in a million, but its natural incidence in the population at large is even greater: 10 to 20 cases per million adults.

In the United States we now have immunization guidelines for 17 vaccine-preventable diseases. Benefits for all those vaccines far outweigh any risks. During your next office visit, make a point to ask your doctor what if any shots or boosters you need (not all vaccine protection lasts forever), especially against tetanus, diphtheria and whooping cough; pneumonia; hepatitis A and B; shingles; and the human papillomavirus.

Copyright 2011. Consumers Union of United States Inc.