Jacobson v Massachusetts at 100 years: police power and civil liberties in tension.

A century ago, the US Supreme Court in Jacobson v Massachusetts upheld the exercise of the police power to protect the public's health. Despite intervening scientific and legal advances, public health practitioners still struggle with Jacobson's basic tension between individual liberty and the common good. In affirming Massachusetts' compulsory vaccination law, the Court established a floor of constitutional protections that consists of 4 standards: necessity, reasonable means, proportionality, and harm avoidance. Under Jacobson, the courts are to support public health matters insofar as these standards are respected. If the Court today were to decide Jacobson once again, the analysis would likely differ--to account for developments in constitutional law--but the outcome would certainly reaffirm the basic power of government to safeguard the public's health.