The first smallpox prevention methods were inoculations, intentional infections with active diseased matter that typically caused a mild illness and would later result in immunity. Modern epidemiologists believe that inoculated patients were less likely to contract a fatal case of smallpox because they contracted the disease through skin contact, not inhalation. However, due to extreme disparities in the type and amount of virus used, health practitioners could offer no real prediction of how severe a case a given patient might contract after being inoculated. Inoculation differs from vaccination, which uses a standard dose of dead or weakened virus culture and therefore poses a much lower risk of fatal infection. After a smallpox vaccine was developed in the 1790s, inoculation gradually fell from favor and was eventually banned in numerous jurisdictions.