Many were killed by infectious diseases such as smallpox and measles. There were diseases&colon; cholera, measles, smallpox, and dysentery. The settlers brought new infectious diseases such as smallpox and measles. Possible diseases include bubonic plague, smallpox and malaria. Among the plethora of diseases that caused childhood death were measles, influenza and smallpox. Epidemics accidentally introduced by the Spanish included smallpox, measles and influenza. Many slaves died from diseases such as smallpox and typhoid fever. Native Hawaiians had no resistance to Eurasian diseases, such as influenza, smallpox and measles. Serious outbreaks of smallpox and pneumonia killed many. Prevention was primarily by the smallpox vaccine. The exact origin of the modern smallpox vaccine is unclear. There are side effects and risks associated with the smallpox vaccine. In 1903 Shaw joined in a controversy about vaccination against smallpox. If successful, inoculation produced lasting immunity to smallpox. Despite this, controversy over smallpox inoculation intensified.