Kasahara Ryōsaku was limited in his ability to share the vaccine by his role as an envoy and deputy of the domain. Although he was a town doctor by status, he had been ordered and funded to obtain the vaccine by the domain, and thus had to fulfill the domain's needs by bringing the vaccine to Fukui. At the same time, Kasahara was also indebted to his professional network of physicians of Dutch medicine, which included his teacher Hino Teisai and Hino's other pupils. These physicians eagerly awaited transfers and Kasahara was aware of the importance of this network for his own work. In his 1848 proposal for importation of the vaccine from China, he proposed distributing the vaccine to physicians along the way from Nagasaki to Fukui to be prepared for the event of a sudden disruption (Fukui-ken Ishikai 1968, 175). Rather than prioritizing the domain's territorial claim and rejecting his colleagues' requests, he emphasized that some sharing with knowledgeable people in other territories was in fact in the domain's best interest.
On 11/1, 1849 (lunisolar calendar), while Kasahara was still in Kyoto, three physicians including Hino Teisai's younger brother Katsumin visited from Osaka and Sakai and asked Kasahara for a transmission. Kasahara accepted their request after some hesitation. In a written statement addressed to the two men from Osaka, he stressed that he had not yet completed his mission of bringing the vaccine to Fukui, hinting that he considered any distraction from that mission as potentially problematic. Yet, he added that he had decided to approve this transmission because he had been ordered to establish a vaccination clinic in Kyoto to serve as a resupplier for Fukui, and that the same logic might be applied to Osaka (Kasahara, Kasahara Hakuō-hitsu senkyōroku, 5-6).
Upon transmission, Kasahara issued a certificate that specified the purpose of the Osaka transfer as “multiplication” (hanshoku no tame). On 11/7, Osaka's first vaccination clinic opened in the neighborhood of Furutemachi with a formal ceremony, with Kasahara Ryōsaku and Hino Teisai in attendance. Bound by his loyalty to his domain and his loyalty to the more far-flung network of fellow professionals, Kasahara connected the two by emphasizing the spatial requirements of vaccine preservation.