Vidyya Medical News Service
Volume 6 Issue 85 Published - 14:00 UTC 08:00 EST 25-Mar-2004 Next Update - 14:00 UTC 08:00 EST 26-Mar-2004
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Germany starts clinical development of a new tuberculosis vaccine

With some 2.5 million deaths and 9 million new cases annually, tuberculosis (TB), along with HIV/AIDS, is responsible for the greatest number of infectious disease victims worldwide. Of particular concern is the fact that an ever-increasing number of pathogens are becoming resistant to conventional medications. Figures from the World Health Organisation indicate that some 50 million people around the globe are infected with these multi-resistant strains. An effective tuberculosis vaccine, therefore, is more urgently needed than ever.

To mark World Tuberculosis Day on March 24th, a consortium of business and research centres have launched a programme to develop just such a vaccine. Scientists at the Max Planck Institute for Infection Biology (MPIIB) in Berlin, under the direction of Prof. Stefan H. E. Kaufmann, have developed a highly promising vaccine candidate. And now, Vakzine Projekt Management GmbH (VPM) has acquired a worldwide licence for several patents from Max Planck Society. VPM was founded by Germany's Federal Ministry for Education and Research (BMBF) as part of a national vaccine initiative. In collaboration with MPIIB and the German Rearch Centre for Biotechnology (GBF) VPM will manage the pre-clinical and clinical study program.

"For our new tuberculosis vaccine candidates we are relying on genetically modified variants of the live BCG vaccine that has been in use since 1921," says MPI director, Prof. Dr. Stefan Kaufmann. "The vaccine consists of an attenuated bacteria that is very closely related to the TB pathogen, Mycobacterium tuberculosis. BCG has a proven safety record for many decades, but unfortunately it lacks effectiveness," notes Kaufmann, adding that children can be protected against certain forms of TB only. There is no protection at all against pneumotuberculosis, by far the most common form of the disease.

The protection provided by the presently existing BCG vaccine is assumed to be limited because the BCG bacteria are hidden in the body cells inside so-called phagosomes. The group of Professor Kaufmann, therefore, has inserted a gene coding for the protein listeriolysin. "This protein causes perforation of the phagosomes thus making BCG cells available to the immune system to build up immune protection," says Dr. Leander Grode, now project manager at VPM and co-inventor of the new strain. "Preclinical experiments have already indicated an increased immune response," he notes.

Estimates suggest that one third of the world's population is infected with TB bacteria. Initially, the pathogens are dormant. The disease later erupts in about 10 percent of those infected, who develop open, contagious tuberculosis. With more than 7,500 cases annually in Germany the disease is nowhere near eradication. "Medical need is high and on the rise with the spread of multi-resistant strains," emphasises VPM Managing Director, Dr. Albrecht Läufer, "therefore, a successful TB vaccine has considerable economic potential." VPM's goal is development up to Phase II, followed by licencing out to an industrial partner. Joint early stage development with partners is also under consideration.

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