Vaccines: History, Safety, and How They Work

Introduction to Vaccines

Almost everyone receives vaccines at some point in their lives. People often want to understand what vaccines are made of, whether they are effective, and whether they are safe. They also want to know why there are so many different vaccines and whether all of them are truly necessary. More often than not, people want to understand exactly what they are receiving when they get a vaccine (Offit and Bell, 2003).

In recent years, new vaccines have become available; some vaccines have been replaced with others, and some have been withdrawn. Parents have had concerns about the safety of an additive used in many vaccines, and a number of publications have suggested that it may be linked to sudden infant death syndrome, persistent joint disease, aggressive behavior, autism, diabetes, and multiple sclerosis (Offit and Bell, 2003). So, what exactly are vaccines?

A Brief History of Vaccination

A vaccine is any preparation intended to produce immunity to a disease by stimulating the production of antibodies. Vaccines contain solutions of killed microorganisms or their derivatives. The most common method of administering vaccines is by injection, though several are given by other means. Vaccines are widely and routinely administered worldwide, based on the general principle that it is better to prevent people from getting sick than to treat them after they become ill. Suffering, disability, and death are thereby avoided. Vaccination prevented approximately two million deaths in 2002. Additionally, the spread of infection is reduced, pressure on health systems is relieved, and resources are regularly saved that can be directed toward other health services (Vaccines, 2010).

The practice of introducing a small quantity of the smallpox virus — either by inhaling it through the nose or by making a series of small punctures in the skin, a process called variolation — in order to produce resistance to the disease appears to have originated in the tenth or eleventh century in Central Asia. This practice spread into Asia and Africa by way of the nasal method. In Europe, the skin-puncture technique was used. Variolation was introduced in England in 1721.

FDA Regulation and Advisory Bodies

In 1798, Edward Jenner, having observed the success of variolation with cowpox in protecting against smallpox, began performing vaccinations against smallpox. This was the first organized attempt to control a disease through vaccination. In 1885, Louis Pasteur developed the first inoculation to protect people against rabies. Toxoids against diphtheria and tetanus were introduced in the early 1900s; the bacillus Calmette-Guérin (BCG) vaccine against tuberculosis was introduced in 1927; the Salk polio vaccine in 1955; and vaccines against measles and mumps in the 1960s (Vaccines, 2010).

Vaccines, like all products regulated by the FDA, undergo a rigorous evaluation of laboratory and clinical data to ensure their safety, effectiveness, purity, and potency. Vaccines approved for sale are also required to undergo further studies in order to better assess the vaccination and to address specific questions about the vaccine's safety, efficacy, or potential side effects. According to the Centers for Disease Control and Prevention, vaccinations have reduced preventable infectious diseases to record lows, and today very few people experience the devastating effects of measles, pertussis, and other diseases. The Center for Biologics Evaluation and Research (CBER) regulates vaccine products. Many of these are childhood vaccines that have contributed to a substantial reduction in preventable illnesses (Vaccines, Blood & Biologics, 2010).

Even after a vaccine is approved by the FDA, physicians typically wait until it is formally recommended before administering it to their patients. There are three primary committees that recommend the use of vaccines for children: the Advisory Committee on Immunization Practices (ACIP), the Infectious Disease Committee of the American Academy of Pediatrics, and the American Association of Family Physicians. Each of these advisory bodies is composed of ten to fifteen doctors and scientists with extensive expertise in infectious diseases, immunology, and vaccine research. The data evaluated by these groups is broader than that reviewed by the FDA. While the FDA focuses on whether vaccines work and are safe, advisory bodies also consider how much vaccines cost and how to make the best use of them. While the FDA examines only risk-benefit ratios, advisory bodies also analyze cost-benefit ratios (Offit and Bell, 2003).