Latent tuberculosis and tuberculosis vaccine

Tuberculosis can exist in two forms: latent tuberculosis and active tuberculosis. In the first case, one can get infected with the bacteria but the disease does not manifest. Once ingested in the body, the tiny particles that carry this bacterium can have a very harmful effect on the organism’s immune system, it is attacked and weakened and also more accessible to other diseases.

A healthy immune system could fight off this infection, not exterminating it completely from the body because it is too strong, but managing to keep it through natural mechanisms under control; in this way the bacteria becomes dormant – in a pause state, one might say, it does not multiply or spread through the body. In this state, the infected person doesn’t feel in any way different, there are no symptoms and no discomfort.

When the immune system can’t cope with the infection anymore, latent tuberculosis becomes active tuberculosis, thus sickening the body. The bacterium starts to grow, infecting the lungs or even further, through the circulatory system – reaching other organs.

One can find out if they carry the disease if they are, by chance, diagnosed with it. It is obvious that latent tuberculosis is more threatening that the active form due to the fact that is almost impossible to diagnose. Scientists refer to this people as carriers; they can have the infection for a life time, without knowing and also without manifesting the disease or any symptoms at all. In this case, it is very hard to transmit it to a non-infected organism.

To prevent getting infected or even having this disease, scientists have discovered one vaccine called BCG in the early 1920’s. The vaccine was at first extensively tested on animals and then administered orally mainly to petite children and infants to prevent them from getting the disease, because their immune system is still developing, they are very susceptible to getting infected.

Studies have shown that sometimes even with the vaccine, people can still test positive on the tuberculosis skin test, because it was proved that the vaccine itself can produce an infection, especially in people with compromised immune systems – the elderly, AIDS patient, etc. This infection could be fatal for the sick person.

The tuberculosis vaccine has been a much debated theme in the medical field. At the beginning, the vaccine had proven to have about an 80% rate of success against pulmonary tuberculosis.

Nowadays, tuberculosis vaccine has no longer the same effect in preventing the disease. Even so, studies have been conducted that demonstrate, that although the vaccine has lost its effect on that type of tuberculosis, its properties are beneficial for extra pulmonary tuberculosis – the types of tuberculosis that no longer affect just the lungs, but also other organs/tissues in the body.

The question: why did this tuberculosis vaccine stop working against the disease was answered after some period of time. It was stated that it started to restrain the immune system’s response therefore it stopped combating the disease.

In current times, some countries still give this vaccine to small children, in the hope that it may help in preventing the infection. Scientists have big hopes for the future; they trust to discover a vaccine that will definitely destroy the bacterium from the human body without other negative consequences.