Clinical trial capacity remains challenge for TB vaccine development

Tallinn, Estonia: While progress is being made in the development of new vaccines against tuberculosis (TB), sufficient clinical trial capacity remains a major challenge, researchers reaffirmed at the Second Global Forum on TB Vaccines in Tallinn, Estonia (21-24 September 2010).

Scientists from around the world presented the latest developments in their research on new TB vaccines. Eight vaccine candidates were presented, which are now all tested on humans in various stages of clinical trials, many in Africa. Currently the most advanced vaccine candidate is the MVA85A vaccine developed by Oxford University.

While the current TB vaccine candidates have shown promising early-stage results on safety and immunogenicity in studies conducted at well-established world class TB vaccine research sites, further tests are required and additional clinical trial sites will be needed to meet the demand. The already long and complicated process of testing vaccines is made more challenging by a general lack of capacity for clinical trials worldwide, the researchers acknowledged.

"It is important to involve local communities from the very beginning," stressed Dr Tom Evans, MD, Chief Scientific Officer at Aeras Global TB Vaccine Foundation in a presentation.

Evans mentioned the need to address language issues, local (traditional) medical practices, local perceptions about giving blood and participating in clinical trials as necessary steps needed to avoid possible pitfalls. But even logistical problems such as power grid problems and limited access to electronic data, or unexpected situations such as worldwide travel problems and instability of governments can influence the course of clinical trials.

According to Robert Nakibumba, Community Representative to the New Vaccines Working Group at Stop TB Partnership, creating 'minds for a new TB vaccine' on community level is a challenge as well. "Many people think: there is a TB vaccine already, why you come up with a new vaccine?" he said in a later session at the meeting. "We have to tactfully explain to the community the limitations of BCG, they must know the existing tool is not effective."

BCG (Bacille Calmette Guérin) is the only currently available vaccine against TB. It is widely used around the globe and protective against severe forms of TB in children. But it is not effective enough against pulmonary TB in adolescents and adults, the most common and most infective form of TB worldwide.

Nakibumba also underlined the importance of involving local communities. "They are not only patients or participants in clinical trials. They are going to get the vaccine, they are serious stakeholders."

The Second Global Forum on TB Vaccines in Tallinn, Estonia, last week brought together around 200 scientists, clinicians, manufacturers, NGOs and governmental institutions from around the world. They reviewed the progress made in vaccine development in the past decade and look forward to the challenges and opportunities ahead. [CNS]

Babs Verblackt - CNS
(The author writes for Citizen News Service (CNS) and is an Associate Communications at TuBerculosis Vaccine Initiative – TBVI)

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