In the nineteenth century, Japanese and Dutch physicians made several attempts to import the smallpox vaccine from Batavia in the Dutch East Indies (Jannetta 2007, 78-94). The Dutch East Asia Company, and later the Dutch state, maintained a trading factory in Nagasaki, on a small island called Deshima, and dispatched about two ships per year to go to Japan from Batavia, the colonial headquarters of the Dutch East Indies. But the vaccine was a fragile piece of cargo. The sea journey from Batavia to Deshima took over a month, and the hot and humid climate during the sailing season made it difficult to keep the virus alive. The search for the right vehicle thus led Japanese physicians to consider the respective merits of two types of bodily secretion containing the virus: either fluid extracted from a ripe pock, or dry scabs covering a healing pock mark.

The first to import smallpox vaccine to Nagasaki was Dutch physician Jan Cock Blomhoff. Stationed at the Deshima trade factory for several years, he was eager to bring the new treatment to Japan and received several shipments of liquid vaccines and equipment he had requested from the colonial authorities in Batavia between 1820 and 1823. But he failed to immunize any children, most likely because the vaccine had lost its efficacy at sea. Subsequent attempts by others to ship fresh lymph from Batavia were equally unsuccessful.

In the 1840s, Japanese specialists of Dutch medicine intensified their importation efforts. They were aware of the vulnerability of fresh vaccines and asked the Dutch to deliver cowpox scabs instead. By that time, Japanese specialists already had significant experience with Chinese-style variolation, which involved pulverizing dried smallpox scabs and blowing the powder up a child's nostril. While such exposure to the human smallpox virus was more dangerous than vaccination with the cowpox virus, it had given physicians the opportunity to observe that scabs were easier to store and transport than fresh lymph. In China, where vaccination was being practiced since 1805, physicians had made similar observations for cowpox and transmitted their insights through published writings to their Japanese peers. While the Dutch seem to have hesitated to move away from the transport of liquid vaccines, they eventually fulfilled the Japanese request for scabs.

After several failed attempts, a ship from Batavia reached Deshima in the summer of 1849 with both lymph and scabs on board. The shipment was received by the ordering party—Narabayashi Sōken, a physician serving the lord of Saga domain—as well as the Dutch factory physician Otto Mohnike. The two men used both types of secretion to vaccinate local children, but only the vaccine from the scab produced a reaction. Narabayashi's son Kensaburō thus became the first Japanese child to be successfully vaccinated with the cowpox virus, and became a source for further arm-to-arm transmissions (Jannetta 2007, 78-87, 129-133). Scabs thus proved a feasible means of storage and long-distance transmission.

Vaccinations in the Dutch East Indies

In Java, smallpox vaccinations had been taking place since 1804. In that year, the Dutch governor-general had put a group of children on a ship to Mauritius to import the vaccine through arm-to-arm transmission. It was common at the time to use groups of children for overseas shipments of vaccines (see, for example, the case of the Spanish empire; Mark and Rigau-Pérez 2009, 69). During the British occupation of Java between 1811 and 1816, lieutenant-governor Thomas Raffles established a thorough vaccination program on the island that partly relied on training local religious leaders and mandating regular reporting of vaccination drives to the colonial administration. The Dutch colonizers maintained that program after retaking control from the British in 1816. Their vaccination efforts encountered many problems such as resistance from parents and local elites, a lack of training among vaccinators, and logistical difficulties while trying to penetrate the outer islands. Yet, Batavia was the most accessible source of supply for Japanese physicians, thanks to Japan's officially sanctioned trade link with the Dutch as well as active support from Dutch factory doctors in Nagasaki (Neelakantan 2010; Jannetta 2007, 47-50, 78-80).