A vaccine is a substance containing bacteria attenuated or dead, inoculated to humans or animals in order to immunize against a disease. Already in the eleventh century, the Chinese had a form of inoculation of a vaccine, more or less effective against smallpox. A vaccine against smallpox is made in 1796.
When the antigen (contained in the vaccine) enters the body, the immune system forms antibodies able to kill an intruder. The system retains the antibodies and provides protection against the disease covered by the vaccine.
The vaccine is usually inoculated by injection but also orally, especially in animals. Vaccines against the virus are most effective.
Preventive vaccination has helped reduce the incidence of several diseases, including tetanus, pertussis, polio ...
In several countries, some vaccines are compulsory (diphtheria, tetanus, polio ...). Some vaccines are mandatory for tourists, by country (cholera, yellow fever, typhoid, meningitis ...).
Some diseases, like smallpox, have been completely eradicated and no longer require the vaccination.
The more recommended vaccines (some mandatory) protects against measles, polio, tetanus, pneumococcus, pertussis, hepatitis B, typhoid, meningitis and influenza.
11 juin 2010
| The text above is for information purposes only. Only a doctor can diagnose a disease. No treatment (medication or scheme) should be undertaken without consulting a health professional. |