Because many vaccine-preventable diseases are now uncommon in the United States, some people wonder if it’s necessary to keep up with immunizations. The answer is yes. Many infectious diseases that have virtually disappeared in the United States can reappear quickly. The germs that cause the diseases still exist and can be acquired by people who aren’t protected by vaccination.
As travelers unknowingly carry disease from one country to another, a new outbreak in the United States may be only an airplane trip away. From a single entry point, an infectious disease can spread quickly among unprotected individuals.
The persistent threat of disease is just one reason public health officials recommend vaccinations. Vaccines provide a number of benefits to individuals, communities and the world population.
Many people have questions and concerns about vaccine safety. A common fear is that vaccines may trigger serious side effects or even cause disease. In fact, vaccines are extremely safe. Before they can be used, they must meet strict safety standards set by the Food and Drug Administration (FDA). Meeting these standards requires a lengthy development process of up to 10 years followed by three phases of clinical trials.
Once vaccines are licensed and made available to the general public, the FDA and the Centers for Disease Control and Prevention (CDC) continue to monitor their safety. Furthermore, vaccines are subject to ongoing research, review and refinement by doctors, scientists and public health officials.
Your chances of being harmed by a disease are far greater than your chances of being harmed by a vaccine used to prevent disease.
Vaccines are highly effective. Most childhood vaccines are effective in 85 to 99 percent or more of children who receive them. In some instances a vaccine provides only partial immunity. It doesn’t prevent the disease, but it often lessens the duration of the illness and the severity of the symptoms.
In addition to being potentially fatal, many infectious diseases can cause permanent harm. Polio can cause paralysis. Meningitis can cause deafness. Measles can cause brain damage and death. Hepatitis can cause liver damage. Vaccines prevent these serious complications.
Take, for example, the Haemophilus influenzae type b (Hib) vaccine. Before the vaccine became available, this bacterium caused about 20,000 serious infections in American infants and children each year. Hib meningitis killed 600 children annually and left many survivors with deafness, seizures or mental disability. Immunization has reduced the incidence of Hib disease by almost 99 percent.
Immunizing also protects the health of your community. In any community, you’ll find a small number of people who shouldn’t be vaccinated — for example, individuals who are allergic to an ingredient in a vaccine or who have a condition that precludes certain vaccinations. These people depend on others not passing disease on to them.
If 95 percent of the people in a community are immunized, unprotected individuals are much less likely to be exposed to the germ, so they have a smaller chance of becoming infected. This is called herd immunity.
Immunization protects more than one city, one country and one generation. Its benefits can extend across the world and into the future. The long-term goal of an immunization program is to completely eliminate a disease. At least in one instance, this goal has become a reality. The worldwide eradication of smallpox is a success story of modern medicine.
Smallpox was devastating to humankind for centuries. It spread in epidemics and killed as many as 30 percent of its victims. The disease caused severe headache, fever and a red, blistering rash that often left disfiguring scars on its survivors. Up to one-third of people with the disease were blinded from corneal infection.
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