Compulsory vaccination exists in all 50 states of the United States, particularly as a condition of admission to public school. Vaccine manufacturers lobby for these laws to maximize revenue on their products.
While proponents of vaccination argue that it helped eradicate smallpox and polio, others cite improved hygiene as significant factors. Regardless, new vaccines are being required of schoolchildren for numerous diseases that most will never be exposed to, such as Hepatitis B, and diseases that are not dangerous to schoolchildren, such as chickenpox. Compulsory vaccination has also been required for diphtheria, pertussis, measles, mumps, and rubella.