Smallpox 1718. In 1721, Cotton Mather and colleagues provoked controversy in Boston by inoculating hundreds. In 1796, Edward Jenner, a doctor in Berkeley, Gloucestershire, rural England, discovered that immunity to smallpox could be produced by inoculating a person with material from a cowpox lesion. Cowpox is a poxvirus in the same family as variola. Jenner called the material used for inoculation vaccine, from the root word "vacca", which is Latin for cow. The procedure was much safer than variolation, and did not involve a risk of smallpox transmission. Vaccination to prevent smallpox was soon practiced all over the world. During the
German retribution against Poles who helped Jews possible to organise public protests against deportations of the Jewish population. Calculations by Teresa Prekerowa show that only 1% to 2.5% of the adult Polish population was involved in helping Jews. However, the number of helpers was also very small in the countries of Western Europe - although hiding Jews there was associated with an incomparably lower risk. Assuming the percentage of the population of European countries, which in 1945 was made up of Jews who survived the Holocaust, Poland did not differ from the average in other occupied states. On the other hand, in the Netherlands, where few Jews