"Judaism traditionally expects certain actions of its believers to maintain health. Pikuakh nefesh, acting to save one’s own or another’s life, is a primary value, a positive commandment (mitzvah aseh). Judaic principles emphasize the community benefits of disease prevention in a manner superior to individual preference, based on scriptures such as Leviticus 19:16 (Table 1C) that counsel not to stand idly by while a neighbor is in trouble. Jewish scholars applied this directive to encourage smallpox vaccination in previous eras."