A new clinical trial has been launched in Oxford to determine the effectiveness of delivering tuberculosis (TB) vaccines through inhalation.
The study is being conducted by researchers at the University of Oxford’s Jenner Institute, who are giving BCG, the current licensed vaccine against tuberculosis, to people who have already had BCG vaccination once before. They will compare whether giving it by inhalation is better at protecting people against tuberculosis than giving it into the skin.
As the natural route of infection with tuberculosis is through inhalation of droplets into the lungs, it is hoped that this study, which delivers BCG by the same route, will be more effective at stimulating the immune system.
Professor Helen McShane, the Oxford BRC’s Chief Executive, is leading this study. She said: “TB kills more people than any other infectious disease and we urgently need better vaccines. This important new study will help us to see whether giving BCG more than once stimulates a stronger immune response and whether giving it by inhalation is better than giving it into the skin.
“Small studies like these are really important to help us understand the immune response in people and allow us to design and test better vaccines.”
This study will also explore whether giving people with type 2 Diabetes BCG in the skin stimulates as strong an immune response as giving BCG in the skin to people without diabetes. People with type 2 diabetes are known to be more likely to get TB and this may be partly because the BCG vaccine does not work as well in this group.
The study will recruit healthy volunteers, with and without type 2 diabetes, who have previously been vaccinated with BCG. They will be split into three groups of 12 volunteers each. If eligible, volunteers will receive BCG vaccine either as an injection in the skin or as an inhaled vaccine. All participants will be followed up for six months after receiving BCG with close monitoring for side-effects and to evaluate the immune response.
TB remains one of the top 10 causes of death worldwide, and the largest infectious killer. BCG given as a single dose under the skin is the only vaccine currently licenced for use against TB, but it is not always protective. The BCG vaccine works well against disease in childhood, but it is not good enough at protecting against disease in adulthood, which is when most TB deaths occur.
Aye Thu, Clinical Research Fellow at the Centre for Clinical Vaccinology and Tropical Medicine, said: “Despite the BCG vaccine being around for more than 100 years, Tuberculosis remains the leading cause of death from an infective cause. A significant proportion of the population infected with TB continue to get sick and die even with TB medication.
“Having a new way of optimising the BCG vaccine will ultimately improve the health of people all over the world. This study will give the participants an opportunity to get involved in testing an exciting new way of delivering BCG vaccine through the aerosol route.”
Another similar trial conducted by the same Oxford team used aerosol BCG as a challenge agent.