The discovery of the immunological mechanism of vaccination and the different ways of applying it are historically linked to the fight against smallpox.
According to the WHO , the administration of a small amount of the virus by nasal inhalation or by small incisions in the skin, useful to create resistance to a disease began in Central Asia from the 10th century.
The practice through the nasal route was extended to other places in Asia and Africa, while in Europe, skin incisions were used. However, the epidemics of smallpox that hit Europe in the late seventeenth and eighteenth centuries were decisive for the ravages they caused among the population.
It is estimated that because of the various plagues that visited the old continent, between 10 and 20% of the child population died, while an unknown number of adults lost their lives or were disfigured due to the disease.
In 1798, the English rural doctor Edward Jenner He observed that people who happened to be infected with secretions from cowpox pustules did not usually get the disease.
Jenner he realized that the contact of the organism with these vaccine strains, besides not representing a danger for the human being, was enough for the immune system to generate defenses and face epidemics with a certain immunity. This was the first systematic effort to fight a disease through immunization.
The official medicine, decided that this method will be called as a vaccination, in honor of Jenner cows. From the year 1800, almost all European countries were gradually introducing the practice of vaccination, especially in children.
In 1885, Louis Pasteur he developed the first vaccine to protect human beings against rabies. Diphtheria and tetanus toxoids were introduced at the beginning of the 20th century; the vaccine with the bacillus Calmette-Guérin , against tuberculosis , in 1927; the vaccine polio of Salk in 1955 and vaccines against measles and the parotitis in the sixties.