Anthrax vaccines known to result in far less scarring, and greatly reduced mortality, in comparison with the naturally acquired disease. The English physician Edward Jenner (1749–1823) had also discovered (1796) the process of vaccination by using cowpox to give cross-immunity to smallpox and by Pasteur's time this had generally replaced the use of actual smallpox material in inoculation. The difference between smallpox vaccination and anthrax or chicken cholera vaccination was that the weakened form of the latter two disease organisms had been "generated artificially", so a naturally weak form of the disease organism did not need to be found. This discovery revolutionized
Smallpox early as 1803, the Spanish Crown organized the Balmis expedition to transport the vaccine to the Spanish colonies in the Americas and the Philippines, and establish mass vaccination programs there. The U.S. Congress passed the Vaccine Act of 1813 to ensure that safe smallpox vaccine would be available to the American public. By about 1817, a very solid state vaccination program existed in the Dutch East Indies. In British India a program was launched to propagate smallpox vaccination, through Indian vaccinators, under the supervision of European officials. Nevertheless, British vaccination efforts in India, and in Burma in particular, were hampered