Immunization: Why vaccines are so important to safeguarding health

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Immunization: Why vaccines are so important to safeguarding health

Immunization benefits far outweigh the risks of infectious disease or vaccine-related adverse events.

Immunization is one of the best ways you can protect yourself and your children against infectious disease. By stimulating your body's natural resistance to disease — thereby creating immunity — vaccines are your first line of defense against the likes of polio, measles, mumps, rubella, influenza, tetanus, diphtheria and pertussis.

Were it not for the widespread use of vaccines in the U.S., a far greater number of deaths would occur during childhood and many more people would be living with chronic and often crippling aftereffects of disease.

What immunization can achieve

The immediate result of immunization is the prevention of dangerous, potentially life-threatening infectious illnesses. The long-term goal of an immunization program is the complete eradication of a disease.

Immunization success: Proof through history

In 1979, the World Health Organization (WHO) announced the success of a 10-year program to eradicate smallpox. Smallpox had been a devastating disease for centuries. It killed 30 percent of those who were infected. Most survivors were left with disfiguring scars. Many were blinded from corneal scarring.

When the campaign to wipe out smallpox started in 1967, an estimated 10 million to 15 million cases of smallpox were estimated to occur worldwide each year. The last reported case of smallpox occurred in Somalia in 1977. The treatment and survival of this individual signaled the end of one of the deadliest and most feared diseases in history. The success of the smallpox campaign increased efforts to immunize against other infectious diseases. Most notable is the Global Polio Eradication Initiative. At the time the program was launched in 1988, polio was widespread, with cases reported in 125 countries. Only six countries reported widespread polio as of June 2005. Efforts remain under way to achieve a polio-free world by the end of the decade.

Within the United States, vaccines have reduced the incidence of measles by 98 percent and invasive Haemophilus influenzae type b infection in children by more than 99 percent. Because of immunization, the incidence of diphtheria dropped from 206,000 cases and 15,520 deaths in 1921 to an average of just two to three reported cases each year since 1980.

Many remain unimmunized

If you're like most people, you trust the advice of your doctor. You've probably weighed the risks and benefits and believe that immunization — for yourself and your children — is the right thing to do. Furthermore, you understand that having your children vaccinated also helps protect others. It's true that a small number of people shouldn't be vaccinated — for example, those who may be allergic to a vaccine ingredient — and remain susceptible to the disease. These individuals depend in part on others who have been immunized not passing the disease on to them.

Still, a number of children in the United States are missing one or more recommended immunizations. This may be due to inconvenience, missed appointments or forgetting when the next shot is due. Or it's possible that some who lack access to health care aren't aware of clinics that might be available to them. It may also result from parents misunderstanding the risks of not immunizing.

The risks of disease outbreaks

In some respects, immunization programs have been a victim of their own incredible success. Because many vaccine-preventable diseases are now uncommon in the United States, you may feel less urgency about getting yourself or your children immunized. You might never have known of a case of diphtheria, polio or tetanus. You may feel that stringent levels of cleanliness and sanitation are enough to control disease. And you may feel that simply living in a highly vaccinated society protects you. However, these reasons are insufficient. Only after a vaccine is used widely is there a significant drop in the incidence of any vaccine-preventable disease.

In fact, many infectious diseases that have virtually disappeared in the United States can quickly reappear. That's because the germs that cause the diseases still exist in other parts of the world, making a new outbreak in the United States only a plane trip away. Travelers can unintentionally carry disease into the United States. From a single entry point, an infectious disease can spread quickly, particularly among those who are unprotected.

Those who aren't properly immunized are much more likely to catch a disease. As recently as the early 1990s, several serious outbreaks of measles occurred in the United States because of inadequate immunization.

Vaccine safety concerns

Despite the success of vaccines, public concern about vaccine safety continues. Many adults fear that introducing a vaccine into themselves or their children may trigger serious side effects or even cause the disease itself. Hearing or seeing media reports regarding a sickness or severe reaction of a child who has just been immunized can raise your level of concern.

Before vaccines can be used, they must meet strict safety standards established by the Food and Drug Administration (FDA). Meeting these standards requires a lengthy development process that can take up to 10 years. During this time the vaccine undergoes three phases of clinical trials. Once vaccines are licensed and put in use, the FDA and the Centers for Disease Control and Prevention (CDC) continue to monitor their safety. Vaccines are also subject to ongoing research and review by doctors, researchers and public health officials.

Nevertheless, vaccines, like prescription drugs, aren't completely free of possible side effects. Most effects are minor and temporary, such as a sore arm, mild fever or swelling at the injection site. Serious side effects, such as a seizure or a high fever, are extremely rare. When reports of serious reactions do appear, they receive careful scrutiny from the FDA.

In the case of an adverse event associated with a vaccine, you can report the event to the Vaccine Adverse Event Report System, which was created jointly by the FDA and the CDC.

Last Updated: 08/18/2005
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