New TB vaccine developed using a genetically modified adenovirus

Mar 20 2009

McMaster University researchers are about to launch Canada's first tuberculosis (TB) vaccine clinical trial with a vaccine totally designed, manufactured and tested within McMaster.

"The exciting thing for McMaster is that this is translational research that has gone from the basic science where the vector has been designed here at McMaster, then manufactured here, with all the pre-clinical studies done at McMaster," said Dr. Fiona Smaill, a professor of medicine and chair of the Department of Pathology and Molecular Medicine.

Development of the vaccine for the landmark trial was led by Zhou Xing, a professor in the Department of Pathology and Molecular Medicine. The vaccine was manufactured in the Robert E. Fitzhenry Vector Laboratory of the Institute of Molecular Medicine and Health on campus, Canada's first university laboratory certified to provide vectors (delivery agents) for use in clinical trials in humans. Most of the pre-clinical testing of the vaccine was undertaken at McMaster.

The phase 1 clinical trial, which has the approval of Health Canada, will begin to recruit 48 healthy volunteers between 18 and 55 years of age in mid-April. Over 12 – 18 months researchers will evaluate the safety of the new vaccine (currently called AdAg85A vaccine) and assess blood samples from vaccinated healthy human volunteers to determine if the vaccine is generating a desired immune response. The trial will be conducted by a team of infectious disease physicians, vaccine manufacturing specialists and immunologists at McMaster.

The announcement of the new TB vaccine trial coincides with World TB Day on Tuesday, March 24, when health authorities and researchers around the world will be raising awareness about the need for new TB vaccines.

Today, TB ranks second only to HIV among infectious killers worldwide, claiming nearly two million lives annually. The disease is evolving faster than therapies with the emergence in recent years of strains that are resistant to every last one of the antibiotic defences.

The McMaster researchers developed the new TB vaccine using a genetically modified adenovirus – a virus responsible for the common cold. After removing a small portion of the gene, they inserted part of the TB gene responsible for immunity. "It is natural ways of making the body use its own immune machinery," said Smaill, a physician and infectious disease specialist.

"Based on all pre-clinical studies carried out on animals, including mice, guinea pigs (who are very prone to TB) and cattle, this vaccine appears to be a very promising candidate vaccine," Xing said.

The vaccine, manufactured to clinical grade standards at McMaster, has passed all the testing required for its use in humans, Smaill said. Along with regulatory approval from Ottawa, the TB vaccine trial has been approved by the research ethics board at McMaster University and Hamilton Health Sciences (HSC).