History of Vaccines: Part 1

Vaccination

The concept of immunization, or how to artificially induce the body to resist infection, received a big boost in 1796, when physician Edward Jenner inoculated a young boy in England and successfully prevented him from getting smallpox. Jenner used a lancet to scratch some infected material from a woman with cowpox (similar to smallpox) under the boy’s skin.

Can’t Catch This: Immunity and Immunization

Lack of immunity to disease has helped to decide the fate of entire communities, from smallpox among the Indians in the New World to syphilitic soldiers in the Old. Most people have some amount of natural immunity. The human body can take care of itself in many circumstances—cuts, colds, and minor infections disappear without major upheaval. In other cases, the body has little or no naturally occurring immunity. So if you are exposed to diseases such as polio, influenza, smallpox, hepatitis, diphtheria, measles, or whooping cough, you will probably get sick with it unless you have been immunized.

Immunization refers to the artificial creation of immunity by deliberately infecting someone so that the body learns to protect itself. An important part of the history of immunization has been determining how to get the immunizing agent into the body. The skin, which keeps germs and injurious substances out, is also a barrier to getting medicines and vaccines into the tissue where they can work. Physicians have used varying methods to create immunity where there was none.

The Future Has a Past

In the 19th century, use of the hypodermic syringe was limited by dependence on large needles that could rust or snap in two, glass barrels that cracked, and tips that leaked. Before disposable needles in the 1960s, needles needed to be sharpened and sterilized. Since then, technological improvements include sharper, thinner needles and safety features. Still, more than a few people would like to avoid a shot in the arm.

Hypodermic injection remains the most common method of getting through the skin, but it is not the only technology for immunization. Engineers and scientists continue to search for alternative routes into the body, such as through the mouth or nose. Continuing to solve the technological problems is critical for countries in which illness and death rates are high as a result of measles, maternal tetanus, and other preventable diseases.

A successful instrument or system must get the vaccine into the body with minimal disruption and be cost-effective for use with billions of people. Perhaps the most important problem today—preventing reuse of syringes to avoid cross-contamination—was not even imagined in the 19th century.