Oxford University improving future TB vaccine development

They have for the first time set up a controlled human infection model that invades the body through the lungs, mirroring the method of real-world TB infections.

This clinical trial used the BCG vaccine, a TB vaccine, which was delivered to participants through aerosol.

This application flips the conventional method of injecting vaccines into the arm and more accurately reflects the natural process of TB infection.

This is the first step towards establishing a benchmark that can be used to test the effectiveness of new TB vaccines.

The human challenge model has significantly contributed to the development of vaccines for malaria and typhoid.

This model allows the scientific community to choose the most promising vaccines that should be considered for widespread trials, offering a tool in the fight against diseases like TB where creating a vaccine is a challenge.

Unlike for malaria and typhoid, it would be unethical to give those involved in the trial live TB due to a lack of efficient treatments.

The BCG vaccine was used in this trial because it is a live attenuated strain of Mycobacterium bovis – which is related to Mycobacterium TB, the bacterium which causes TB in humans – and BCG is known to be safe in humans.

Researchers enlisted healthy people who hadn’t received the BCG treatment in the past.

They were given BCG by aerosol by using a nebuliser into the lungs.

To ensure the safety of the participants, the aerosol dose was gradually increased, discovering the highest tolerable quantity that did not cause severe side effects.

The study was led by professor Helen McShane, professor of vaccinology in the Nuffield Department of Medicine (Image: Richard Cave)

Professor Helen McShane, professor of vaccinology at the University of Oxford said: "When we did lung washes of the participants, we recovered BCG, which is a positive sign in a challenge study.

"If we hadn’t found BCG in the lung fluid, we would not have been able to move forward with this as a model."

Professor McShane added: "TB is back as the number one killer among infectious diseases.

"It’s a really difficult pathogen to make a vaccine for, and human challenge models, such as the one we have trialled in this study will undoubtedly play a vital part in helping us to develop a vaccine.

"For this reason, this is an important first step in establishing that model."

Professor McShane launched another study earlier in the year examining BCG as a vaccine instead of a challenge agent and compared skin injection to aerosol inhalation.