The introduction of the smallpox vaccine to Japan owed much to existing networks among Japanese specialists of Dutch medicine [Janetta]. Most physicians of the Tokugawa period spent some time training with one or more prominent doctors outside their home region. Often, they moved to one of the larger cities for a few years in their youth and then returned to practice medicine at home, only to move again if they desired further training. In the process, most doctors forged permanent ties with teachers that situated them within wider, trans-regional lineages of medical learning. The network of Dutch medicine specialists, which consisted of many interconnected student-teacher relationships, was a site of particularly lively exchanges of knowledge and ideas.

At the same time, physicians in Tokugawa Japan were also part of localized groups of medical professionals. These groups comprised domain and town doctors of all specialties and served as vehicles for both occupational self-government and seigneurial control. They were status groups in the sense that they situated their members within the structure of Tokugawa rule and managed their members' status and public obligations. While these groups were structured hierarchically and dominated by the domain doctors, all members participated in the tasks of self-government and consensus-building, drawing on their shared medical knowledge.

Broadly speaking, there were two types of medical professionals in Tokugawa Japan: domain physicians, who directly served the lord and received stipends according to rank, and town and village physicians, who lived among commoners and primarily treated commoner patients. Both types, however, performed certain duties for their lords as mediated by their status group. In addition to self-control, they were often expected to treat prisoners, for example, or accompany the lord on his travels or pay their respect at the palace at certain times of the year.

In the course of the nineteenth century, many feudal rulers in Japan intensified their oversight of medical practice in their territories. In the castle towns of Fukui and Fuchū, for example, domain and town doctors began to coalesce around newly established medical academies and exercised stricter control over the practices of village doctors and the sale of medicinal herbs to domain subjects. Medical academies issued rules that defined physicians' respective responsibilities within the group. In Fuchū, physicians affiliated with the academy referred to themselves as a shachū (society) [Umihara].

The status groups of physicians were organized by domain. When Kasahara Ryōsaku, a town doctor of Fukui domain, brought the smallpox vaccine to Echizen, he established a regional network of vaccinators that rested on top of the local status groups of doctors. To explore this new network, go directly to "A New Regional Network of Vaccinators". Or use the link below to continue on the pathway, "The Networks and Vehicles of Vaccine Transmission."