A beneficial role of BCG vaccination on the outcome of anti-tuberculosis treatment

Dr. Jeremiah Kidola

The vaccine

Since the BCG vaccine was first introduced in 1921 over 3 billion doses of vaccines have been administered in the fight against Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB). This makes the BCG vaccine the most widely used vaccine worldwide. The BCG vaccine protects primarily against meningeal and disseminated TB in children, but has also been shown to provide a varying degree of protection against pulmonary TB in adults.

It was initially assumed that the protective effect of the BCG vaccine lay in its ability to reduce pulmonary TB lesions, and thus limit the ability of the bacteria to multiply and spread during the course of TB disease. Recently, it has been found that the vaccine also has a protective role against the infection itself caused by M. tuberculosis.

Newly discovered positive effect

Dr Kidola has discovered an, until now, unknown positive effect of the BCG vaccine which was recently published in the prestigious international journal 'THORAX'.

In a prospective study of 546 tuberculosis patients in Tanzania it was shown that sputum positive (infectious) patients with a visible BCG scar, are 3 times more likely to convert to sputum negative than patients without a visible BCG scar during of the intensive phase of anti-TB treatment (2 months). This effect is independent of HIV status and CD4+ cell count.

Previous studies have shown that patients who are still sputum positive after 2 months of anti-TB treatment run a high risk of relapsing after treatment. Thus, this newly discovered finding of a beneficial role for BCG vaccination for the treatment of pulmonary TB is important for future TB control and vaccination programs.

Click here to read the article in its entirety.

The article has also been commented in an editorial in Thorax: BCG vaccination: 90 years on and still so much to learn. . . (Ajit Lalvani, Saranya Sridhar).

The clinic in Tanzania.