BCG vaccine 400 per 100,000 in that higher risk context). The age of the person and the frequency with which BCG is given has always varied from country to country. BCG is prepared from a strain of the attenuated (virulence-reduced) live bovine tuberculosis bacillus, "Mycobacterium bovis", that has lost its ability to cause disease in humans. Because the living bacilli evolve to make the best use of available nutrients, they become less well-adapted to human blood and can no longer induce disease when introduced into a human host. Still, they are similar enough to their wild ancestors to provide some degree of
Inoculation the sprouts", an idea of transplanting the disease which fit their conception of beansprouts in germination. Needham quotes an account from Zhang Yan's "Zhongdou xinshu" (種痘新書), or "New book on smallpox inoculation", written in 1741 during the Qing dynasty (1644–1912), which shows how the Chinese process had become refined up until that point: Two reports on the Chinese practice were received by the Royal Society in London in 1700; one by Dr. Martin Lister who received a report by an employee of the East India Company stationed in China and another by Clopton Havers. But no action was taken. According