Vaccination is a means by which a person’s immune system is stimulated to produce chemicals - known as antibodies - that will combat a future infection. These antibodies are a healthy body’s natural response to invading viruses and bacteria, but exposure to certain dangerous pathogens for the first time can be deadly. Vaccinating individuals against specific diseases means that their immune systems are primed in advance to respond immediately should they be exposed to the disease at a later date.
To immunise against viral diseases - such as rabies, polio and measles - the vaccine usually incorporates virus particles that have been weakened or killed. To provide immunity against bacterial diseases - such as tuberculosis, diphtheria and cholera - introducing an inactivated portion of the bacteria, or its toxic products, can stimulate antibody formation. Most vaccines are usually delivered via injection. Exceptions include the polio vaccine, which is taken orally. An individual is usually vaccinated in infancy and often in a combination form such as the MMR vaccine against measles, mumps and rubella.
Although the range of vaccines available has increased greatly since Edward Jenner developed the first one - against smallpox - effective vaccines for certain widespread diseases such as HIV/AIDS and malaria remain elusive and access to existing vaccines is also highly dependent on where an individual lives. Despite global vaccination campaigns, many people - particularly children - die each day from diseases that they could have been vaccinated against.
BibliographyM Mackett and J D Williamson, Human Vaccines and Vaccination (Oxford: Bios Scientific Publishers, 1995)
Molecules produced by the body which attach themselves to the micro-organisms that cause disease and destroy them.
A tiny particle made up of DNA/RNA and a protein coat. Viruses infect animals, plants, and micro-organisms and cause many diseases, including the common cold, influenza, measles, chickenpox, AIDS, polio and rabies. Many viral diseases can be controlled by means of vaccines.
Micro-organisms which can cause disease but have an important role in global ecology.
Rabies is a disease which infects domestic and wild animals. It is a virus transmitted to other animals and humans through close contact with saliva from those infected (i.e. bites, scratches, licks on broken skin). Once symptoms of the disease develop, rabies is fatal.
Disease caused by a virus most commonly found in children. Measles is spread through airborne fluids. In roughly the last 150 years, measles has been estimated to have killed 200 million people worldwide.
Human Immunodeficiency Virus (HIV) is a virus that weakens vital cells in the immune system, and leads to AIDS. There are two strands: HIV-1, which leads to immunity suppression; and HIV-2, which is not as potent and is only common in West Africa. HIV is spread through direct contact with bodily fluids.
Acquired Immune Deficiency Syndrome (AIDS) is a disease caused by infections resulting from a weakened immune system due to the HIV virus. It leads to failure of the immune system and is usually fatal. It is spread through direct contact with bodily fluids.