New tuberculosis vaccine discovered?

Researchers test new tuberculosis vaccine

05/09/2011

Researchers have developed a new vaccine against tuberculosis. As the scientists of the Albert Einstein College of Medicine New York in the current issue of the journal „Nature Medicine“ They have successfully tested a tuberculosis vaccine on mice, which makes the pathogens recognizable to the immune system and thus enables them to be controlled by the body's own immune system.

The new tuberculosis vaccine has proved to be extremely efficient in mouse experiments and also offers clear advantages over previous vaccines, such as the so-called Bacille Calmette-Guérin (BCG) developed almost a century ago, reports study director William Jacobs. BCG was used as the only tuberculosis vaccine for decades, but provided only 50- to 80-percent security against tuberculosis, according to US researchers. Jacob also explained that conventional tuberculosis vaccines often caused relatively severe side effects, and that scientists have been looking for years for a new vaccine (vaccine).

Here, the approach of the US researchers may possibly be the breakthrough, because unlike BCG, the new tuberculosis vaccine not only slows down the growth of bacteria in the body, but is able to kill the pathogens in infected tissue completely, said study director William Jacobs. Although the novel vaccine in the study did not show the same effect in all mice, the US researchers see in their vaccine the basis for future tuberculosis prevention. As Jacobs emphasized, generates „neither BCG nor any of the vaccines currently being researched have such an obvious or so long immunity“. While further research is needed, it appears that the novel vaccine is available „something we have been dreaming about for years: longer protection and bacteria-killing immunity,“ said the scientists of the Albert Einstein College of Medicine.

Vaccine exposes the tuberculosis bacteria
The researchers around William Jacobs have their novel tuberculosis vaccine from the Mycobacterium smegmatis, a harmless relative of tuberculosis bacteria (Mycobacterium tuberculosis) won. By blocking the so-called esx-3 gene in the Mycobacterium smegmatis, the scientists were able to disguise the bacteria and make them recognizable to the immune system. Through genetic manipulation, the immune defense was then able to successfully fight the bacteria, said William Jacobs. The researchers used the genetically modified pathogens of Mycobacterium smegmatis as part of their study to vaccinate mice and then infected the animals with tuberculosis pathogens. The animals were actually immune to infections with the dangerous bacteria, said the US researchers. In the mice that survived the longest, the pathogens were no longer detectable in the tissue, so the statement of the scientists. The protective effect is essentially caused by the so-called helper T-cells, which activate other immune cells and help them in the identification of the pathogen, write William Jacobs and colleagues. According to the US researchers, the T helper cells were also able to transmit the tuberculosis protection after initial vaccination with the novel vaccine. By injecting purified T helper cells into other previously unprotected animals, they became immune to the dangerous infectious disease, the researchers said.

Nine million tuberculosis infections annually
Tuberculosis is still relatively widespread, according to the World Health Organization (WHO), especially in Asia, Africa and the Eastern European countries. Every year around nine million people are infected with tuberculosis and more than 1.7 million people die as a result of the infection. As typical signs of as well as consumption or „the moths“ known disease includes lung infections with persistent cough, chronic fatigue, weight loss, fever and nocturnal sweat attacks as well as a painful stinging in the chest. About 50 percent of untreated tuberculosis diseases are fatal, warned the Robert Koch Institute (RKI), whose namesake had discovered the tuberculosis bacteria in 1882, during the World Tuberculosis Day in March this year. Anyone who has discovered signs of tuberculosis should urgently consult a doctor.

Safer and more efficient tuberculosis vaccines required
While in Germany, the number of tuberculosis diseases has been declining significantly for years, according to WHO in Africa, Eastern Europe and some Asian countries, there is a continuous increase in tuberculosis-related infections and deaths. The US scientists around William Jacobs are particularly worried about the situation in southern Africa. Because here the increased number of HIV infections is associated with an increased proportion of fatal tuberculosis diseases. The weakened immune system of AIDS patients can not oppose the tuberculosis pathogens and correspondingly high is the number of fatal tuberculosis diseases, so the statement of the US researchers. Therefore, according to William Jacobs and colleagues, sustainable tuberculosis vaccine protection would be particularly urgent. But just in the regions with the most tuberculosis infections and deaths, the conventional BCG vaccine was found to be unreliable, said the US researchers. Because a protective effect is often barely measurable or not at all. In addition, according to the scientists BCG is due to possible side effects for patients with the immune deficiency disease AIDS limited use. Especially in HIV-infected children threaten serious side effects, said William Jacobs, thus underlining his statement that „new tuberculosis vaccines that are safer and more efficient than BCG, badly needed“ become. (Fp)

Read about tuberculosis:
Tuberculosis: the most dangerous infectious disease
RKI warns against tuberculosis in Germany
Study: Tuberculosis increases lung cancer risk

Image: Thomas Siepmann