Bacillus Calmette-Guerin
(BCG)
Description
Others simply refer to the BCG or Bacillus Calmette–Guérin as vaccine for preventing such a severe condition known as tuberculosis (TB). It is a French-derived appellation attributable to its founders, Albert Calmette and Camille Guérin, who crafted it during the early 1900s by attenuation of Mycobacterium bovis.
What is TB (tuberculosis)?
The infection is known to be an issue first in the lungs, and then bacteria can migrate to other body parts such as bones, brain, and kidneys. TB travels through the air when someone with active TB coughs, sneezes, or talks. It’s most probably a kind of health problem that still prevails throughout many parts, especially in developing countries.
A few persons having TB bacteria may not feel sick yet. These are known as “latent TB.” They do not show any signs and cannot spread. But if the bacteria work, it can make you very sick and even kill you if you do not get help.
What is the BCG shot?
The BCG vaccine is prepared from a less virulent strain of the bacterium Mycobacterium bovis. This bacteria closely resembles the bacterium Mycobacterium tuberculosis, which causes tuberculosis in humans. The bacteria in the vaccine are not harmful, therefore will not make you sick but then, they will help your body to learn how to fight the bacteria that cause TB.
In areas where TB is common, infants and young children are usually immunized with the BCG vaccine. Sometimes, people who are at much risk of getting TB adults or older children may also be given the vaccine.
BCG is administered by a single shot given in the upper arm. A small bump or blister may appear at the site that later becomes a scar. Most people believe that this scar proves that the vaccination was given accurately.
At a lot of places, children receive BCG vaccination as part of their routine immunization schedule; hence, usually, shortly after birth.
How well does it work?
It protects children well from severe forms of TB, particularly TB meningitis and TB that spreads throughout the body. However, how well it stops TB in adults, especially the lung form of TB, varies according to the people and the place.
Although efficacy may be attenuated in some regions, overall, BCG provides strong protection. This vaccine won’t stop all kinds of TB, but it is still very valuable for saving lives and cutting the number of serious cases of TB in children.
The BCG vaccine need not be universal; it is not given to individuals residing in countries where tuberculosis is not common. Generally, they do not receive BCG; rather, they are tested for exposure to TB and receive treatment if needed.
The WHO does not recommend BCG vaccination for all infants and young children everywhere as a routine but does for those living in areas where TB is endemic. Health workers, as well as travelers to areas with high rates of the disease, may be advised to receive the vaccine if there is vulnerability.
Effects of BCG
Any vaccine has side effects, but generally, they are mild. The most common side effects are:
- Erythema or swelling at the injection site
- An ulcer or sore that does not heal for a long time
- A keloid
It must be noted that serious side effects are hardly encountered save for extreme situations in which infections at the injection site and lymphadenitis appreciably develop whereas such cases are a rarity and usually the benefits of the vaccine far outweigh the risks.
People with compromised immunity, for example, HIV-infected individuals, may inadvertently not receive the BCG vaccine as it may pose a problem to them.
BCG in Other Uses
Another interesting fact is that BCG is used for various medical applications. One of the most common uses is for the treatment of bladder cancer. BCG is instilled into the bladder so that it could help the immune system attack cancer cells. This mode of treatment has been age-old and has shown response in certain types of bladder cancer.
How BCG could be a help for other conditions, for example, diabetes and autoimmune diseases, is something else that the researchers are currently trying to figure out. These studies show that BCG may have other applications other than just preventing tuberculosis, however more research is required.
BCG is an important, much-popular vaccine that saves millions of children worldwide from severe forms of tuberculosis. It may not prevent all cases of TB, especially in adults, but still, it is one of the best ways to fight the disease in the first place.
It is public health important and stops the spread and effects of TB by using it in certain groups of people. There may be additional benefits beyond tuberculosis as research and development progress from the BCG vaccine.