Vaccination is the process of administering weakened or dead pathogens to a healthy person or animal, with the intent of conferring immunity against a targeted form of a related disease agent. It succeeded and is distinct from inoculation. In common speech, 'vaccination' and 'immunization' generally have the same colloquial meaning. Vaccination efforts have been met with some resistance since its inception. Early success and compulsion brought widespread acceptance and mass vaccination campaigns were undertaken which have greatly reduced the incidence of many diseases in many areas. The eradication of smallpox, which was last seen in a natural case in 1977, is considered the most spectacular success of vaccination. Some people assert that childhood vaccination plays a role in autoimmune disease and autism though large-scale scientific studies have not shown a link. Some major contemporary research in vaccination focuses on development of vaccinations for diseases including HIV and malaria.