[Attempts to inoculate against plague in the eighteenth and nineteenth centuries].

In the middle of the 18th century, inoculation against smallpox became more and more common, and attempts were also made to test the same principle, viz. inoculation with the agents causing the disease for other human and animal diseases. It was tried for rinderpest, measles and sheep pox. In addition, there were some suggestions for using the principle against the plague. The disease had disappeared from Western Europe by this time, but still raged in eastern countries, such as Russia. However, the government rejected the proposal for trial inoculations in Moscow. During the first half of the 19th century, the plague was still widespread in the Middle East, where different European doctors worked on combatting it. The first documented inoculation trial was carried out by a certain Mr. Whyte, an English physician who inoculated himself and four assistants in 1801. All five died a few days later. In the following years, more tests were carried out, inter alia: in 1802, by Desgenettes, the chief physician of the French army in the Middle East; in 1803, by Eusebio Valli, an Italian physician in Constantinople; in 1818 and 1819 by Sola, a Spanish physician in Tangier. However, none of these tests produced clear results. During the epidemic in Egypt in the 1830s, further inoculation tests were carried out by a group of French plague specialists with the main aim of establishing whether the plague could be transmitted between humans. These tests did not result in any clear conclusions either. Following the discovery of the plague bacillus at the end of the 19th century, a number of different live and dead vaccines were developed, and were also used in endemic areas, but the level of efficiency has never become very clear. This is not really surprising, as even the disease itself often does not provide strong immunity, and reinfections are by no means uncommon.