Definition
Merck meningitis vaccine recall!
To be vaccinated is to be pre-exposed to an infectious agent in order to prevent a serious or life-threatening infection. This is most often done for viruses since their ability to infect relies on an individual not having been previously exposed to that particular agent. The word vaccine comes from the first virus, vaccinia (cowpox), used to provide immunity (protection) from disease. Edward Jenner was an English doctor who, in the late 1700’s, discovered that inoculation (infection by having viral material come into direct contact with the blood of the person to vaccinate) with the pox virus made people immune to smallpox infection. This technique was tested using different kinds of viral material (live virus, weak virus, dead virus, viral proteins as an example) and by the mid 1900’s vaccination for common life-threatening infections was widely available. It wasn’t until the 1970’s that the first disease was eradicated, smallpox, but no other has been removed from the global human population though there are currently campaigns to eliminate polio and yellow fever in parts of the world where they still exist.
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