Problems with contaminated or inert vaccine frustrated many physicians and led to widespread public anxiety about the safety of vaccination in 1901–2. Although many people worried about vaccination and avoided it, only a few actually stepped up to organize antivaccination societies, write about the dangers of vaccination, and lobby their state legislators for repeal of compulsory laws. Those who adopted a public stance against vaccination had varying motivations. Some antivaccinationists emphasized the antidemocratic nature of compulsion and coercion, others resented any state laws or regulations that interfered with private medical judgment about their patients, and still others questioned the propriety of compelling vaccination when the state could not ensure its safety. Many antivaccinationists felt that public health officials and medical societies displayed an unscientific attitude by refusing to acknowledge well-documented problems with vaccination. By the turn of the twentieth century, a loose network of antivaccination activists and physicians came together in Boston to organize formally as the Massachusetts Anti-compulsory Vaccination Society (MACVS).

Antivaccinationists were not cranks, crazy, or the lunatic fringe, despite the derogatory comments of their opponents. The New Englanders attracted to antivaccination tended to be well educated and socially respected by virtue of their lineage at a time when such backgrounds mattered a lot. Some of them were physicians trained at the best schools in the United States and even Europe. It would be a mistake to assume that their rhetoric about civil rights meant that they all opposed state action in public health, social justice, or the economy. These Massachusetts antivaccinationists were not antigovernment libertarians, but instead thoughtful people who posed legitimate questions about state interference in individual health matters, matters that they believed should remain between the patient and his or her doctor. They called for government regulations to ensure better living and working conditions for the poor as well as pure food and water. They supported traditional public health measures by insisting on strict adherence to quarantine, isolation of the sick, street cleaning, and disinfection— all tactics that invaded, disrupted, or damaged businesses, lives, and property. Some of them demanded government regulation of the vaccine market. In this, they looked to the past, to time-honored police power traditions rather than to the new public health that focused on individuals as carriers of disease. They wanted their local governments to do more, not less, to control smallpox.