Glossary

Vaccination:
Is the administration of antigenic material (the vaccine) to produce immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by a pathogen. Vaccination is considered to be an effective and cost-effective method of preventing infectious diseases. The material administrated can either be live but weakened forms of pathogens (bacteria or viruses), killed or inactivated forms of these pathogens, or purified material such as proteins. The word vaccination was first used by Edward Jenner in 1796. Louis Pasteur furthered the concept through his pioneering work in microbiology. Vaccination (Latin: vacca—cow) is so named because the first vaccine was derived from a virus affecting cows—the relatively benign cowpox virus—which provides a degree of immunity to smallpox. The British physician Edward Jenner tested the possibility of using the cowpox vaccine as an immunization for smallpox in humans in 1796. In the 19th century Louis Pasteur discovered that chickens, injected with an old culture of chicken cholera were no longer susceptible were for new infections with cholera.  Because Pasteur saw the resemblance with the cowpox, he named it vaccination.

Virus:
A virus (from the Latin virus meaning toxin or poison) is a microscopic infectious agent that can reproduce only inside a host cell. Viruses are very small organisms, many are useful, others harmful or even dangerous.  One human cell could have a million viruses.  Viruses stick to proteins, carbohydrates or lipoids on the membrane of the cell.  A hepatitis virus specifically lives in liver cells.  Viruses can mutate very fast.  Our modern lifestyle and the increasing globalization are causing the fast spreading of viruses.  The malicious Ebola virus and West Nile virus are examples of that.

Immune system:
The immune system protects the body against infections. The immune system is a collection of biological processes within an organism that protects against disease by identifying and killing pathogens. It detects a wide variety of agents and needs to distinguish them from the organism’s own healthy cells and tissues in order to function properly. White blood cells and antibodies identify and eliminate pathogens, either by attacking the pathogens through contact or by engulfing and then killing the microorganisms. Antigenes can be toxins, viruses, bacteria, molds, but also transplanted organs. Detection is complicated as pathogens can evolve rapidly, producing adaptations that avoid the immune system and allow the pathogens to successfully infect their hosts. If the immunity is not sufficient, a virus can cause sicknesses and for instance a flu epidemic.

Flu epidemic:
Flu is the popular word for influenza, originating from the Latin verb influo, meaning ‘stream out to something’.  Different kind of Flu viruses can cause a lot of misery.  Annually the seasonal flu results world-wide in hundreds of thousands deaths.  Epidemic originates from  the Greek epi (under) and demos (people).  The virus is spread ‘under the population’. Birds are the most important reservoir of flu virusses, perhaps as a result of the bio-industry.  Bird flu refers to a series of viruses that targeted especially birds (ducks, swans, geese and chickens).  These viruses can infect other animals too, as pigs, and also people.  Since 1997 (Hongkong) the bird flu virus A- H5N1, mostly reffered as H5N1, infected other animals and people for the first time.  The infected animals were very sick and many had to be slaughtered.  Three times the world was been hit by an influenza pandemic: in 1918 (H1N1, falsely called ‘Spanish Flu’); in 1957 (H2N2) and in 1968 (H3N2).  The ‘Spanish flu’ caused 20 -30 million deaths.

Pandemic:
If the flu virus travels the world and is spreading through human populations in a large region or even continents, it is called a pandemic, derived from the Greek pan (all) and demos (people).  In the popular belief it was thought demons could be cause of it. It resulted in panic and complete fear in the whole population.  A flu pandemic is a world-wide flu epidemic, caused through a new flu virus (subtype of the influenza A-virus), that spreads in the same way as the seasonal flu: coughs and sneezing.  Because the virus is new, the immune system does not recognize it and is not sufficient.  It is the World Health Organization (WHO) that according to ’scientific criteria’ decides when a epidemic becomes a pandemic, and which measures must be taken.  The WHO is a specialized agency of the United Nations, set up in 1947. Powerful oil baron John D. Rockefeller played a key role. He also played a role in the influential foreign-policy think tank ‘The Council on Foreign Relations’ (CFR) and the ‘Trilateral Commission’, from which a lot of presidents, secretary-generals of the UN and NATO are recruited.  In case of a pandemic, only vaccination is considered.