Immunisation is the deliberate stimulation of the body's own defence mechanisms to become more effective in recognising and fighting off disease-causing agents such as bacteria and viruses. It works by introducing a weakened or ‘killed’ form of the disease-causing agent into the body, which stimulates the body to produce antibodies against it. Once the body has produced the antibodies, it becomes immune to the disease if it is exposed to it a second time.
The History of Immunisation
The practice of immunisation dates back to the 10th century, when a Chinese emperor tried to protect his people from smallpox by encouraging them to inhale powdered scabs from those who had already recovered from the disease. In 1796, the English doctor Edward Jenner developed a safer form of immunisation against smallpox by injecting a small amount of cowpox, which is similar to smallpox but less severe. This was the first successful use of a vaccine.
Types of Immunisation
Immunisation can be either active or passive. Active immunisation involves giving a person a weakened or killed form of a disease-causing agent, such as a vaccine. This stimulates the body to produce its own antibodies against the disease. Passive immunisation, on the other hand, involves injecting a person with pre-made antibodies to a particular disease.
The Benefits of Immunisation
Immunisation has been incredibly successful in reducing the incidence of many infectious diseases, including polio, measles, whooping cough, and diphtheria. It has saved millions of lives worldwide and has been estimated to prevent up to 3 million deaths each year. It is also cost-effective, as it is much cheaper to immunise against a disease than to treat it once it has occurred.