Vaccines now being tested may be the first of their kind that are safe for those with damaged immune systems, say scientists.
New TB vaccines being tested in South Africa will probably be safe for HIV-positive individuals - unlike the current vaccine - says the director of the South African Tuberculosis Vaccine Initiative, Professor Greg Hussey.
Hussey also said that by 2010 the initiative's vaccine site in Worcester could be running large-scale trials on the efficacy of the experimental vaccines.
"With the resurgence of TB worldwide, scientists are starting to focus on a TB vaccine. The only solution to TB in the medium and long term is a vaccine," he said.
He was speaking ahead of the 38th Union World Conference on Lung Health, held in Cape Town this week. On the first day, the Global Alliance for TB Drug Development announced that a " milestone in the development of faster, simpler TB drug regimens" had been reached with the advancement of two promising TB therapies.
The urgent need for a new strategy in developing TB drugs, and a sharp drop in funding TB research, were raised by major health organisations on the eve of the conference:
Médicins Sans Frontières, backed by TB experts, called on drug developers to test their new treatments on patients who are resistant to existing TB drugs; and The US Aids research think tank, the Treatment Action Group, said that the UK and the US had cut its funding for TB research between 2005 and 2006 - and that overall global public sector support had fallen from 259-million to 244-million despite a sharp increase in drug- resistant TB worldwide.
Dr Karin Weyer, TB research director at the SA Medical Research Council, warned that the recent outbreaks of extensively drug-resistant TB (XDR-TB) could be the tip of the iceberg without a "significant investment in new drugs, diagnostics and vaccines".
The Bill and Melinda Gates Foundation increased its contribution to TB research by more than 36-million to a total of 94-million in 2006.
Weyer said: "XDR-TB transmission is exacerbated by the HIV epidemic. Left unchecked and potentially untreatable, XDR-TB poses serious threats to large areas of sub-Saharan African, Eastern Europe and Southeast Asia."
South Africa was hit by outbreaks of XDR-TB last year. This strain of TB - which is very difficult to treat effectively - has now been identified in more than 40 countries. Even the less severe form, multi-drug- resistant TB (MDR-TB), takes a heavy toll on patients.
Said Dr Eric Goemare, head of Médicins Sans Frontières in South Africa: "With the current MDR-TB drugs, the majority of patients give up halfway, and most of them who are co-infected with HIV don't make it.
‘‘They do not adhere to the treatment and they die before the end of treatment."
An estimated one third of the world's population, about two billion people, are living with latent TB infection. The disease kills more than 1.6 million people every year.