Bacillus Calmette–Guérin vaccine or more commonly known as the BCG vaccine is used against Tuberculosis, offering a maximum protection period of 10-20 years based on geographic location. It’s one of the oldest and widely used vaccines in the world. India first introduced it post-independence in 1948 making it one of the first countries outside Europe to introduce the same.
Of all the vaccines out there the BCG vaccine is the most fascinating one. The vaccine has many unique properties. Firstly its effectivity varies based on latitudes. As one moves towards the equators, it shows minimum effectivity of almost zero. But as you move towards the poles its effectiveness improves to almost 80%. Various theories have been proposed on the subject to explain this phenomenon.
The BCG vaccine consists of weakened mycobacterium bovis cells. In you live in India you will surely have had the vaccine. If you have that vaccine scar on your shoulder then you have had it. It’s probably one of the only other vaccine apart from small pox vaccine to leave such a scar on your shoulder. Its sad however that despite the fact that everyone gets vaccinated due to the fact that we are a tropical country the vaccine has poor effectiveness.
The most fascinating property of this vaccine however lies in its alternative uses. BCG vaccine is used for the treatment of Bladder cancer. As it so happens BCG vaccine is so effective that it is infact the gold standard for bladder cancer! It slashes reoccurrence rates by 67%. Its mind boggling as to how a concoction of weakened TB organisms could possibly act against cancer. I don’t know about you guys but my brain just cannot wrap its self around this fact.
One article said and I quote “…Bladder cancer is the only cancer in which BCG is commonly used. Other agents have been used in bladder cancer, but none has surpassed the effectiveness of BCG…”
If used in the right patients meeting the treatment criteria, BCG can kill 70% of the cancer.
Aside from this the vaccine is also being tried against certain forms of colon cancer.
Currently BCG vaccine is in the second year of its 5 year PHASE II clinical trial for type 1 diabetes. The medical community is going crazy over the type 1 diabetic vaccine which happens to be none other than the BCG vaccine. It appears to somehow kill the auto immune reactive WBCs that would attack the pancreas destroying the insulin producing Beta cells. The data looks very promising, if approved it will change the course of diabetic history.
Science never ceases to fascinate you. It’s just amazing how a vaccine is the standard treatment for a type of cancer and a potential prophylactic for type 1 diabetics.
By Raghuvir Keni
REFERENCES:
1. Brandau Suttmann H. Thirty years of BCG immunotherapy for non-muscle invasive bladder cancer: A success story with room for improvement. Biomedicine & Pharmacotherapy. 2007;61(6):299-305.
2. Bacillus Calmette-Guérin Immunotherapy for Bladder Cancer: Overview of BCG Immunotherapy, Mechanism of Action of BCG, Contraindications to BCG [Internet]. Emedicine.medscape.com. 2016 [cited 13 October 2016]. Available from: http://emedicine.medscape.com/article/1950803-overview
3. Getahun Abate, Daniel F. Hoft. Variations Between Bacillus Calmette-Guérin Strains: Lessons from Tuberculosis Prevention. European Urology. 2014;66(4): 692-3
Nice information, very fascinating
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