New tuberculosis vaccine effective in animal testing

Mar 23 2009

A new tuberculosis vaccine candidate developed by researchers at Canada's McMaster University has proven effective in animal testing, the researchers announced Thursday, the Hamilton Spectator reports.

The vaccine, called AdAg85A, works by injecting a live adenovirus containing the TB gene responsible for immunity. The adenovirus, which is the type responsible for the common cold, would then live long enough to introduce the TB gene and trigger the body's immune response, theoretically resulting in TB immunity.

Although the current BCG vaccine, which has been used for 90 years, offers protection against childhood TB, AdAg85A could be used as a booster shot to protect against adolescent and adult forms of the disease, the Spectator reports. The researchers said they plan to start recruiting volunteers in April for Phase I human trials, which will be conducted over a 12- to 18-month period. For the human trials, researchers will measure the vaccine's safety and ability to trigger an appropriate immune response. According to the Spectator, if AdAg85A proves to be safe, effective and practical to produce and distribute, the team could release the vaccine in about five years or longer.

According to the Spectator, the McMaster researchers are the first Canadian team among about 12 groups worldwide that are developing TB vaccines. Fiona Smaill, chair of McMaster's Department of Pathology and Molecular Medicine, said, "Given the enormous problem that we've got with TB, the more people involved in trying to move the research program forward, the better." She added, "Something has to be done, because we can't keep hoping there will be an announcement around the corner." Zhou Xing -- pathology and molecular medicine professor at McMaster who led the vaccine's development -- added that the team is "very excited" about AdAg85A. According to Smaill, researchers have laid the groundwork for the adenovirus-based vaccine for about 20 years, and the team has conducted the AdAg85A project for the last eight to 10 years (Hemsworth, Hamilton Spectator, 3/20).