Vaccinated

Vaccination is a biological preparation that provides active acquired immunity to a particular infectious disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future.

History

The concept of vaccination was first realized by Edward Jenner who discovered in 1796 that milkmaids who had contracted a milder infection called cowpox did not catch smallpox. Since then, the science of immunology has developed and many successful vaccinations have been created.

Types of Vaccines

There are several types of vaccines. Each type is designed to teach your immune system how to fight off certain kinds of germs — and the serious diseases they cause.

• Live-attenuated vaccines fight viruses and bacteria. These vaccines contain a version of the living virus or bacteria that has been weakened so that it does not cause serious disease in people with healthy immune systems.
• Inactivated vaccines also fight viruses and bacteria. These vaccines are made from the virus or bacteria that has been killed or parts of the virus or bacteria.
• Subunit, recombinant, polysaccharide, and conjugate vaccines use specific pieces of the virus or bacteria — like its protein, sugar, or capsid (a casing around the virus).
• Toxoid vaccines prevent diseases caused by bacteria that produce toxins (poisons) in the body. In the process of making these vaccines, the toxins are weakened so they cannot cause illness.

Benefits of Vaccination

Vaccination has greatly reduced the burden of infectious diseases. It prevents not only morbidity, but also mortality. Vaccination has led to the eradication of smallpox, one of the most devastating diseases in history.

Risks and Controversies

While vaccines are generally accepted by the public, some people and groups oppose vaccination, a phenomenon known as vaccine hesitancy. Vaccine hesitancy often results from fears about vaccine safety.

See Also

• Immunization
• Herd immunity
• Vaccine trial
• Vaccine schedule
• Vaccine-preventable diseases

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