Vaccine

Vaccines: history, principle of action and modern use

Vaccines are one of the most effective ways to prevent infectious diseases. They are preparations prepared from killed or weakened pathogens, as well as their neutralized toxins. When a vaccine is introduced into the body (vaccination), immunity to the corresponding infectious diseases develops - artificially acquired active immunity.

The history of the development of vaccination began more than two hundred years ago. In 1796, the English physician Edward Jenner proposed the first smallpox vaccine, noting that milkmaids who had suffered from a very mild disease, cowpox, did not suffer from smallpox, a dangerous and serious disease. The first vaccine was material obtained from cowpox. At the end of the 19th century, the French scientist Louis Pasteur laid the scientific foundations for the preparation of vaccines and used protective vaccinations against anthrax and rabies.

Currently, the arsenal of modern medicine includes vaccines against many dangerous bacterial and viral diseases, such as plague, cholera, tuberculosis, diphtheria, tetanus, polio, encephalitis and others. There are killed, live, chemical vaccines and toxoids.

Killed vaccines are obtained by treating bacteria or viruses with heat, formaldehyde, alcohol or other methods. Live vaccines are prepared from specially weakened (attenuated) microorganisms that have lost the ability to cause disease, but have retained immunogenic properties, i.e. the ability to cause the formation of protective antibodies against the pathogen. The most common method of weakening the pathogenic properties of microorganisms is their long-term cultivation on artificial nutrient media (bacteria) or in the body of animals (viruses).

Chemical vaccines are specially isolated active components (antigens) of microorganisms or their products. Toxoids are obtained by neutralizing the toxic properties of bacterial exotoxins with formaldehyde.

Vaccines must be effective and safe. Along with vaccines consisting of components of one type of microorganisms