Though Fukui's vaccinators were interested in expanding the town-based system of vaccinations, they were also highly conscious of the risks posed by such expansion. In early 1851, when the vaccine was on the verge of extinction, town officials for the first time raised the idea of vaccination tours to the countryside to treat the rural population, presumably as a way to keep the vaccine in circulation. Hakuō, however, initially rejected the idea. He argued that conditions the countryside would make it difficult to transfer the vaccine every seventh day. He reminded the town officials that distances between villages were too long to reliably “connect the lymph” (tōbyō tsunagi-tome), and warned that the vaccine would go extinct if even one transfer day went unused due to bad weather and other complications. He also pointed out that there were not enough vaccinators available to go into the villages. Fukui's entire chapter might have to go on tour, and that meant that one missed transfer day would extinguish the entire vaccine supply in the domain. In other words, the combination of long distances, low population density, time sensitivity, and the small overall number of vaccinators made rural expeditions a risky endeavor. It was safer to concentrate resources in the castle town for the time being.

The risks of conducting vaccinations at too many places at once are illustrated by the case of Saga domain.

The record of a wealthy peasant household from the village of Futsukaichi suggests that in 1865, rural people were still sending their children to town to get them vaccinated. Futsukaichi was located in the Sakai district between Fukui and the port town of Mikuni, which was part of Fukui domain (see the map on top of the page). In 1865, there seem to have been one vaccination clinic each in Fukui and Mikuni, the latter probably run by Mikuni town doctors with support from wealthy merchant donors. In 1865, the household from Futsukaichi sent three girls and one boy to town to be vaccinated. The three girls went to Fukui the day before vaccination in the company of servants and stayed with relatives overnight. They returned the following day, but went to Fukui again seven days later to get reexamined and supply vaccines to other children. The boy, on the other hand, was taken to Mikuni. It is unclear whether the children's gender had anything to do with the difference in the circumstances of their treatment [Yanagisawa].