/ 29 October 2008

New hope for TB

Recent jubilation over new Minister of Health Barbara Hogan’s call to arms against the Aids epidemic obscured an equally important point the minister made: the urgent need to tackle tuberculosis.

HIV and TB are entwined in South Africa. The country urgently needs to tackle them as a combined problem and two separate epidemics.

South Africa has the highest number of people living with HIV in the world and the fourth-highest number of people with TB.

Nearly half of all TB patients in South Africa are also HIV positive.

One quarter of South Africa’s health budget is spent on HIV and related diseases, with most of it spent on treating TB.

Speaking at an international Aids conference the health minister said: “The TB vaccine was invented before the car. The diagnosis of TB has a similar profile and the medicines used to treat and cure TB are more than 40 years old.

“We urge you to advocate for these technologies because without them the rights to health, life and dignity for millions of people globally cannot be realised.”

We need new, efficient diagnostic tools and new drugs to cure TB quicker. And these drugs must be designed to treat the growing proportion of drug-resistant diseases. But to stop TB we must focus on preventing it. We need a more effective vaccine and we must make it available and affordable.

The current TB vaccine, Bacille-Calmette Guerin (BCG), offers some protection against severe forms of TB in children.

It is given to all infants in South Africa. But BCG is ineffective against pulmonary TB in children and adults, the most common form of the disease.

The bacterium that causes TB infects about one-third of the world’s population, or two billion people. Yet a vaccine that is effective against all strains of the disease in children, adults and people living with HIV may be scientifically achievable within a decade — and South Africa is likely to be its birthplace.

Six potential vaccines are being developed for human clinical trials, under the aegis of the University of Cape Town’s South African Tuberculosis Vaccine Initiative (Satvi). Working with the United States-based not-for-profit organisation, Aeras Global TB Vaccine Foundation, Satvi is testing four vaccines in humans in Worcester.

Three are in phase two trials to confirm their safety. Subject to Medicines Control Council approval, two of them could start additional trials next year to test their efficacy.

One of these candidates will be tested in Johannesburg at the Aurum Institute for Health Research. The study will focus on people with HIV and TB to test whether their weakened immune systems affect the efficacy of the vaccine.

By answering these questions, we ensure that a new vaccine will have a direct impact on TB-HIV co-infection. An expensive vaccine is ineffective, no matter how potent it is.

With this in mind, as the scientific work advances, Satvi, Aeras and their partners and donors must ensure that the new vaccine can be manufactured quickly and inexpensively and distributed to all who need it.

Addressing TB has been on the back burner for too long. The disease will kill an estimated 1,7-million people this year — including 230 000 people with HIV — and infect more than nine-million people.

Hogan recognises that new tools are needed to bring TB and HIV under control. She pledged to support South African scientists and clinicians in the development of new technologies to tackle both diseases.

We are heartened by such leadership and by Hogan’s recognition of the new TB-HIV co-infection epidemic.

The political support she offers, the financial backing by donors, the skills of scientists and the thousands of South African volunteers participating in these trials have increased the chances of ending one of humanity’s oldest and deadliest scourges.

Hoosen Coovadia MD is Victor Daitz chairperson for HIV/Aids research at the Doris Duke Medical Research Institute, Nelson R Mandela school of medicine, University of KwaZulu-Natal, and a member of the board of directors of the Aeras Global TB Vaccine Foundation