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[TALLINN] One of the largest international tuberculosis (TB) gatherings for a decade begins tomorrow to agree on a plan for the development of vaccines.
The ‘Blueprint for TB Vaccines’ will be put together at ‘The Second Global Forum on TB Vaccines: A Framework for Introducing Improved TB Vaccines to the World Community’, in Estonia this week (21–24 September).
"Vaccines are really the ‘plan A’ so far [as] tuberculosis control is concerned," Christopher Dye, director of Health Information in the Office of HIV/AIDS, Tuberculosis, Malaria and Neglected Tropical Diseases at the WHO, Switzerland, told SciDev.Net.
A new vaccine could cut the number of new cases by 90 per cent within a period of three or four decades, he said.
Vaccination would also circumvent weak health systems that hinder efforts to diagnose and treat TB. Hundreds of millions of children could be vaccinated in a short time, he added.
The current TB vaccine, BCG (Bacillus Calmette-Guérin), is effective only in very young children and ceases to work once the child has grown up.
Michael Brennan, senior advisor for Global Affairs at Aeras Global TB Vaccine Foundation, said that there are three priorities for the TB field: to use information from clinical studies to make better vaccines; to keep the pipeline filled with innovative vaccines as more is learned from research, combining the findings with new, needle-free delivery devices; and to understand why vaccines work, by getting to the root of the immune responses that they trigger.
"If we knew what the key immune responses were to effective vaccines it would be easier to evaluate them," he said.
There are around ten vaccine candidates in various stages of clinical trials and about 50 more in development, according to Jelle Thole, director of the TuBerculosis Vaccine Initiative. Thole predicted that there should be a new TB vaccine available within the next five to ten years.
The WHO has set a medium-term goal of eliminating TB by 2050 — which means less than one case per million people, compared with around 1,000 cases per million at the moment.
Although the UN Millennium Development Goal targets for TB are on track, according to a UN report published in June, the disease remains the second largest killer after HIV/AIDS, killing nearly two million people and infecting almost ten million each year. The HIV/AIDS epidemic, and the rise of antibiotic resistance, are further hampering the fight.
"If you had a vaccine against TB it would work for drug-sensitive and drug-resistant TB, and [resistance] then becomes an irrelevant problem, and that is another major advantage of having a vaccine," said Dye.