TB is responsible for the greatest number of deaths from an infectious disease. Each year 54 million people are infected, 6.8 million develop clinical disease and 2.4 million people die of TB. It is endemic in numerous countries.
In developed countries, the incidence of TB showed a dramatic increase in the 1980s and the impact of TB is now compounded by:

• co-morbidity with HIV/AIDS (accounting for around 10% of TB incidence – and approximately 14% of AIDS patients become infected by TB)
• the emergence of multi drug-resistant strains of Mycobacterium tuberculosis (MDR TB now around 2% of incidence and rising)
• high levels of movement of people between countries, including immigration from developing countries.

BCG (Baccille Calmette-Guerin) is the only vaccine currently available against TB. Its protective efficacy has been shown to vary considerably (eg by age and geography). It is often ineffective where there has been prior exposure to environmental mycobacteria. Furthermore, prior exposure to the BCG vaccine itself prevents its use as a booster including in young adults, who are often at greatest risk from infection. The underlying problem is that for BCG to be effective, a productive infection is needed, which does not occur against a background of prior exposure.

Treatment strategies rely on a number of aged drugs taken together. With up to 12 months therapy required, achieving the required level of patient compliance is very difficult. The cost of ensuring compliance (notably “DOT” – Directly Observed Therapy) can be greater than the cost of the drugs themselves. Without eradication, infection persists and onward transmission can resume.

The need for an effective TB vaccine is an established global clinical and economic priority. The initial target is the development of a "booster” to protect against TB in “at risk” people who have already received BCG but who are no longer (or never were) protected, since much of the population has already received BCG.

An additional key need is in immunocompromised people, especially from HIV, unable to be protected or treated with current approaches, against a rising level of resistance.

ImmBio’s HspC technology provides an effective way of presenting antigens into dendritic cells and in a way which is not severely limited by prior exposure to BCG. It thus offers a boost (and subsequently a prime) vaccination approach in line with healthcare needs.

ImmBio was awarded a SMART grant by the UK’s Department of Trade & Industry and initiated studies with the National Institute of Biological Standards & Control. Positive results led to a second Development SMART award. Subsequently, ImmBio has entered into an agreement with the Aeras Global TB Foundation, in turn supported by the Bill & Melinda Gates Foundation.