"Daas Torah" on Vaccinations

Sefer HaBris (1:17:2) is a Torah and science compendium written in the late 18th Century and updated a few years later. It received the approbation of many of the leading rabbis of the day and was studied widely in Jewish communities for many years.

He discusses the invention of the smallpox vaccine, sharing its history and discovery which is widely known. He speaks of how infectious the disease is and of the high incidence of death or permanent scarring and other issues for those who suffered from it. He mentions that it was well known that those who had had the disease once did not catch it a second time. He speaks of the first methods of vaccination and that they were not always effective. He then writes that:

In our generation there is a new cure that protects a person from smallpox which has been tested on thousands and myriads of people who have all turned out healthy, not one of them has died. When the Jewish sages saw that it was tried and tested on a daily basis and had become accepted in all countries and caused no damage they permitted all Jews, on the basis of the Torah, for them and their offspring to direct their physicians to vaccinate them. Many are announcing and encouraging the public about this and informing them that it is an obligation for each person to have himself and his family vaccinated before another smallpox plague breaks out...

The custom of vaccination has begun to spread among Jews and among those who have vaccinated their children are many Rabbis, Geonim, Elders of Israel, and great and honored Torah scholars. The Halacha is in accordance with Dr. Simon of Krakow who wrote in his newsletter New Medicine in 1804 that he encourages all Jews to take this tested cure for themselves and their sons and daughters before there is another outbreak. this is done in Krakow and other Jewish communities...

Even though I promised to write briefly, I have elaborated to encourage people to take this cure, and not to fear any dangers or that there is something sinful... Someone who is lax about this until smallpox affects his children, if they are God forbid injured, he will be brought to justice before Hashem, and be punished by heaven.