TB vaccine in the pipeline
Posted by Miriam Mannak on July 27, 2009
For the first time in eighty years, a new Tuberculosis (TB) vaccine has entered the efficacy stage of a clinical trial in South Africa.
The TB vaccine trial, which has entered phase IIb – was announced during the 5th International Aids Conference on HIV Pathogenesis, Treatment and Prevention – which took place in Cape Town in July 2009.
Clinical trials, during which a potential drug is tested on humans, comprise of three stages or phases. Phase I aims to see whether the drug is safe to use for people, and concerns a small group of volunteers (20-50). Phase II, which aims to determine whether the drug is working, concerns several hundreds of volunteers and is often divided in two sub stages.
While phase IIa assess how well the drug works, phase IIb focuses on how much of the product should be given to a patient. The final stage of the trial or phase III aims at the definitive assessment of the potential new drug. All in all it can take up to twenty years before a drug is given the green light.
The development of a new TB vaccine is crucial, especially in Sub Saharan Africa where so many people living with HIV suffer from TB. The reason for this is that the immune system of someone living with HIV is often not capable of fighting off the TB bacteria. The chance of developing active TB when being HIV negative is about 10 percent in a lifetime. Someone who is living with HIV has a ten percent chance a year to develop TB.
Although the World Health Organisation (WHO) in 2005 declared TB as an emergency in Africa, the region in the world which is hit the hardest by the HIV epidemic, the number of infections as well as the death rates have continued to soar over the past years. About 70 percent of the 14 million people who are co-infected with HIV and TB live in Africa.
According to the WHO, the TB epidemic in Africa is rising by four per cent a year and is now the most common opportunistic infection of people living with HIV.
Copyright content: Miriam Mannak / All Rights Reserved
