A tuberculosis vaccine developed at McMaster University published phase one clinical study results today.

 Tuberculosis is a serious public health threat. One-third of world's population is infected with the organism that causes tuberculosis. The current vaccine used to prevent it is ineffective and high incidence of multi-drug resistant tuberculosis is also a problem.

The new vaccine, based on a genetically modified cold virus, was developed in the lab of Zhou Xing, professor of pathology and molecular medicine and the McMaster Immunology Research Centre, who co-led the phase one study. 

The new vaccine was developed to act as a booster to Bacille Calmette Guerin (BCG), currently the only TB vaccine available. BCG was developed in the 1920s and has been used worldwide. The new "booster" would reactivate immune elements that over time diminish following BCG vaccination.  

Currently the BCG vaccine is part of the World Health Organization's immunization program in Asia, Africa, Eastern Europe and South America, as well as Nunavut, the only Canadian jurisdiction where the BCG vaccine is routinely given because of the high rate of tuberculosis in the territory. It is typically given in the first year of life.

The new vaccine has been more than a decade in the making. McMaster researchers began the first human clinical trial in 2009 with 24 healthy human volunteers, including 12 who were previously BCG-immunized. 

"The primary goal was to look at the safety of a single dose vaccine injection," said Xing, "as well as its potency to engage the immune system."

By 2012 they established that the vaccine was safe and observed a robust immune response in most trial participants. More clinical trials are needed to measure the vaccine's real potential, Xing added. 

"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," said Dr. Fiona Smaill, professor and chair of the Department of Pathology and Molecular Medicine of the Michael G. DeGroote School of Medicine at McMaster.

Published in Science Translational Medicine.