Vaccination

Vaccination is the process of administering weakened or dead pathogens to a healthy person or animal, with the intent of conferring immunity against a targeted form of a related disease agent. The term was coined by Edward Jenner and adapted by Louis Pasteur for his pioneering work in vaccination. Vaccination (Latin: vacca—cow) is so named because the first vaccine was derived from a virus affecting cows: the cowpox virus, a relatively benign virus that provides a degree of immunity to smallpox, a contagious and deadly disease. In common speech, 'vaccination' and 'immunization' generally have the same colloquial meaning. Vaccination efforts have been met with some resistance since its inception. Early success and compulsion brought widespread acceptance and mass vaccination campaigns were undertaken which have greatly reduced the incidence of many diseases in many areas. The eradication of smallpox, which was last seen in a natural case in 1977, is considered the most spectacular success of vaccination. Currently some people assert that childhood vaccination causes some autoimmune disease and autism. Scientific studies have not demonstrated a link; however, the assertion found space in a United States House of Representatives report in 2003 which included the suggestion that mercury derivatives in vaccines might have been a cause of autism.

Some modern vaccines are administered after the patient already has contracted a disease, as in the cases of experimental AIDS, cancer and Alzheimer's disease vaccines. Vaccination given after exposure to smallpox, within the first four days, is reported to attenuate the disease considerably, and vaccination within the first week is known to be beneficial to a degree. The first Rabies immunisation was given by Pasteur to a child bitten by a rabid dog, and then and subsequently post-exposure immunisation to Rabies has generally been followed by survival. The essential empiricism behind such immunizations is that the vaccine triggers an immune response more rapidly than the natural infection itself.

Most vaccines are given by hypodermic injection as they are not absorbed reliably through the gut. Live attenuated Polio, some Typhoid and Cholera Vaccines are given orally in order to produce immunity based in the bowel.

POT-TEXT ASSIGNMENTS:

Exercise 10. Answer the following questions:

What is vaccination?

Who coined this term?

Why is vaccination so named?

What two words have the same colloquial meaning?

What is considered the most spectacular success of vaccination?

When was the eradication of smallpox last seen in a natural case?

What may the childhood vaccination cause currently?

Have vaccination efforts been met with some resistance since its inception?

What derivatives might have been a cause of autism?

In what cases are some modern vaccines administered?

How are the most vaccines given by?

What vaccines are given orally in order to produce immunity based in the bowel?

Exercise11. Join the parts of the sentence in the column A with the correct ones in the column B using the text.

Дата добавления: 2014-12-26