Canadian researchers develop new TB vaccine

Researchers at the Hamilton, Ontario-based McMaster University developed a new tuberculosis vaccine based on a genetically-modified cold virus, according to a study recently published in Science Translational Medicine.

In a Phase I human clinical trial, the researchers established that the new vaccine was safe and prompted a robust immune response in the trial participants. The vaccine was developed to serve as a booster to the only TB vaccine currently available, the Bacille Calmette Guerin vaccine.

"As a doctor who looks after patients who have tuberculosis, including those who are HIV infected, I realize how important it is going to be to control this infection with a good vaccine," Fiona Smaill, the leader of the Phase I clinical study, 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."

The study, which began in 2009, tested the vaccine on 24 healthy human volunteers. Zhou Xing, the co-leader of the study, said more trials are needed to measure the real potential of the vaccine.

"Tuberculosis is a serious public health threat," Smaill said. "One-third of (the) world's population is infected with the organism that causes tuberculosis, and it remains the top infectious killer of people only secondary to HIV; yet, the current vaccine used to prevent it is ineffective."

Another challenge to the TB problem is the rising incidence of multi-drug-resistant TB. A vaccine booster could reactive immune elements that can diminish over time after BCG vaccination.