Tuberculosis vaccine trial has positive results

Results for the Phase One clinical trial of a new vaccine for tuberculosis (TB) have been published by McMaster University, Canada. The new vaccine was initially developed to act as a 'booster' to the only vaccine against the disease that is used around the world. 

Around a third of the population of the Earth is infected with the tuberculosis causing organism, according to the World Health Organization (WHO). While the number of people who die each year as a result of the infection has decreased by around 41 per cent since 1990, large numbers of individuals continue to be diagnosed with TB every year. Some 8.7 million people were diagnosed with the infectious lung disease in 2011. Those that have HIV and weak immune systems are most at risk.   

Currently the only vaccine against TB that is available is the Bacille Calmette-Guerin (BCG) vaccine. BCG is given to people before their first birthday. The newly developed booster vaccine has been developed to reactivate diminished immunisation elements following a person's initial vaccination. It is to be administered years later, when the original vaccine may not be functioning as well as it in the first place.

The development of the new vaccine was led by Zhou Xing, professor of pathology and molecular medicine at the McMaster Immunology Research Centre, who also led the Phase One clinical trial. It was based upon a modified version of the cold virus and has taken over ten years to develop.

Researchers from McMaster started the first human trial of the booster vaccine in 2009, which included 24 healthy volunteers. Of these participants, 12 had been treated with the BCG immunisation. The study was designed to assess the safety of a single dose and its ability to incite an immune response. 

In 2012 it was found that the vaccine was completely safe to use and that most of the participants had experienced a strong immune response to it. According to Professor Xing, more clinical trials are needed to accurately assess the true potency of the vaccine before it can be used commercially.

Dr Fiona Small, professor and chair of the Department of Pathology and Molecular Medicine of the Michael G DeGroote School of Medicine, said: "We are probably one of a few groups in the world who are actually doing bench-to-human tuberculosis vaccine work, and we are excited to be part of this and thrilled that it started at McMaster."