Bacillus Calmette-Guérin

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Image:BCG apparatus ja2.jpg Bacillus of Calmette and Guérin (BCG) is a vaccine against tuberculosis that is prepared from a strain of the attenuated (weakened) live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans by being specially cultured in an artificial medium for years. The bacilli have retained enough strong antigenicity to become a somewhat effective vaccine for the prevention of human tuberculosis. At best, the BCG vaccine is 80% effective in preventing tuberculosis for a duration of 15 years. However, one third of clinical trials have shown no protective effect.^{[citation needed]}

1 History
2 Uses
3 Other tuberculosis vaccines
4 See also
5 References
6 External links

[edit] History

Albert Calmette, a French bacteriologist, and his assistant and later colleague, Camille Guérin, a veterinarian, were working at the Pasteur Institute in Lille in 1908. Their work included the subculturing of virulent strains of the tuberculosis bacillus and the testing of different culture media. They noted that a glycerin-bile-potato mixture grew bacilli that seemed less virulent. They changed the course of their research to see if repeated subculturing would produce a strain that was attenuated to be considered for use as a vaccine. Throughout World War I, the research continued until 1919 when the now non-virulent bacilli were unable to cause tuberculosis disease in research animals. They transferred to the Paris Pasteur Institute in 1919. In 1921, the BCG vaccine was first used in humans.<ref>Fine PEM, Carneiro IAM, Milstein JB, Clements CJ. (1999). Issues relating to the use of BCG in immunisation preogrammes. Geneva: WHO.</ref>

In 1928 it was adopted by the Health Committee of the League of Nations. However, because of opponents of vaccination, it was not widely used until after World War II. From 1945 to 1948, relief organizations (International Tuberculosis Campaign or Joint Enterprises) vaccinated over 8 million babies in eastern Europe and prevented the predicted increase of TB after a major war.

The vaccine proved to be the safest and the most widely used vaccine. The vaccine is very efficacious against tuberculous meningitis in the pediatric age group, but its efficacy against pulmonary tuberculosis appears to be variable. As of 2006, a few countries do not use BCG for routine vaccination, and the USA and the Netherlands have never used it routinely. In the United States, BCG vaccination is not routinely given to adults because it is felt that having a reliable Mantoux test, and being able to accurately detect active disease, is more beneficial to society than vaccinating against a relatively rare (in the US) condition.

[edit] Uses

Tuberculosis: The main use of BCG is for vaccination against tuberculosis. It is not currently recommended in developed countries as routine childhood vaccination because the incidence of tuberculosis tends to be much lower in these areas, with the exception of the UK, where it was (until 2005) routinely given to children aged 10 to 14. It is recommended that the BCG vaccination be given intradermally by a nurse skilled in the technique. Having had a previous BCG vaccination will affect a Mantoux test result: it is generally positive, although a very high-grade reading is usually due to active disease.

Leprosy: BCG has a small protective effect against leprosy of around 26% (Setia 2006).

Cancer Immunotherapy: BCG is useful in the treatment of superficial forms of bladder cancer. Since the late 1980s evidence has become available that instillation of BCG into the bladder is an effective form of immunotherapy in this disease (Lamm et al. 1991). While the mechanism is unclear, it appears that a local immune reaction is mounted against the tumor. Immunotherapy with BCG prevents recurrence in up to ⅔ of cases of superficial bladder cancer. BCG also finds use for immunotherapy of colorectal cancer (Mosolits et al.) and for the treatment of equine sarcoid in horses.

Diabetes, Type I: Clinical trials based on the work of Denise Faustman use BCG to induce production of TNF-α which can kill the T-cells responsible for Type 1 diabetes. Studies using mice have shown that a similar treatment results in a permanent cure for about a third of the test subjects.

[edit] Other tuberculosis vaccines

See: tuberculosis vaccines

[edit] See also

[edit] References

Thomas Dormandy (1999). The White Death: A History of Tuberculosis. Chapter 30 Vaccines. ISBN 0814719279 HB - ISBN 1852853328 PB
Comstock GW. The International Tuberculosis Campaign: a pioneering venture in mass vaccination and research. Clin Infect Dis 1994;19(3):528-40. PMID 95110996.
Lamm DL, Blumenstein BA, Crawford ED, Montie JE, Scardino P, Grossman HB, Stanisic TH, Smith JA Jr, Sullivan J, Sarosdy MF, et al. A randomized trial of intravesical doxorubicin and immunotherapy with bacille Calmette-Guerin for transitional-cell carcinoma of the bladder. N Engl J Med 1991;325:1205-9. PMID 192220.
Mosolits S, Nilsson B, Mellstedt H. Towards therapeutic vaccines for colorectal carcinoma: a review of clinical trials., Expert Rev. Vaccines, 2005;4:329-50. PMID 16026248
Setia, M. S., Steinmaus, C. & Ho, C. S., et al. (2006), "The role of BCG in prevention of leprosy: a meta-analysis", Lancet Infect Dis, vol. 6, no. 3, p. 162-70