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 needle is uncapped. The open end of the uncapped slant culture is then flamed. The slant will be positioned to move up the needle until the inoculation needle tip lightly come into contact with the base surface of the sterile media. The inoculation needle inoculates the sterile agar by the manipulation of the media so that the needle tip grazes the agar surface in a zigzag pattern. Aseptic technique is then applied to the withdrawn inoculation needle. Inoculation of a plate culture is done through the streaking technique to make a streak plate. After lifting the lid so that it hovers