High Quality Content by WIKIPEDIA articles! A vaccine controversy is a dispute over the morality, ethics, effectiveness, or safety of vaccinations. Medical and scientific evidence surrounding vaccinations generally demonstrate that the benefits of preventing suffering and death from infectious diseases outweigh rare adverse effects of immunization. However, since vaccination began in the late 18th century, opponents have claimed that vaccines do not work, that they are or may be dangerous, that individuals should rely on personal hygiene instead, or that mandatory vaccinations violate individual rights or religious principles. These arguments have succeeded in reducing vaccination rates in certain communities, leading to increased outbreaks of preventable, and sometimes fatal, childhood illnesses.