AAHI has developed a safe and immunogenic tuberculosis (TB) vaccine candidate that elicits robust immune responses in adults, in a cost-effective formulation that can withstand extreme temperatures, so that it can efficiently and equitably be made available in low-and-middle income countries most burdened by TB.

AAHI collaborates to protect against tuberculosis.

AAHI’s TB vaccine candidate combines a recombinant fusion protein antigen, “ ID93, “ with AAHI’s synthetic immune-stimulating adjuvant formation, “GLA-SE.” AAHI’s vaccine was originally developed as a formulation provided in two vials – one for ID93 and one for liquid GLA-SE – refrigerated for storage and then mixed immediately before injection. This two-vial presentation demonstrated safety and efficacy in a Phase 1 clinical trial.  A Phase 2 clinical trial is ongoing (NCT02465216), and the two-vial vaccine candidate soon will enter a Phase 3 clinical trial in Korea.

Having demonstrated the safety and immunogenicity of the two-vial TB vaccine candidate, AAHI scientists began to explore ways to reformulate the vaccine to make it temperature-stable, simplify its administration and enable distribution to TB-burdened areas. They ultimately developed a formulation and method by which the antigen and adjuvant formulation components could be combined and lyophilized (freeze-dried), resulting in a “single vial” vaccine.  AAHI’s single-vial vaccine, a dried “cake” combining ID93 and GLA-SE, is reconstituted by mixing with sterile water before injection. The single-vial dried cake can be stored without refrigeration, even at extreme temperatures (37°C and -20°C), for up to three months.  A Phase 1 clinical trial of the single-vial vaccine showed that it maintained the safety profile and even improved upon the immune response profileof the original two-vial liquid formulation (NCT03722472). AAHI’s development and clinical advancement of the novel single-vial presentation of ID93+GLA-SE was supported by the National Institutes of Health (Contract No. HHSN272201400041C). 

In collaboration with the Texas Biomedical Research Institute, AAHI is continuing its work to develop better TB vaccine candidates. The collaboration will test the ID93 and/or related recombinant antigens with new adjuvant formulations to explore potential for improving upon the strength of protection against TB. Scientists will also evaluate a prime-boost vaccine regime, incorporating both a vaccine combining a protein antigen / adjuvant subunit vaccine and a self-amplifying RNA vaccine, using AAHI’s novel Nanostructured Lipid Carrier (NLC) to deliver RNA. The planned studies will also evaluate different routes of vaccine administration in cutting-edge preclinical models, to identify formulations with the most promise for effective protection against TB. This three-year project was recently funded by the National Institutes of Health (R61AI169026).

At the same time, AAHI scientists are working on a third formulation of the ID93+GLA-SE vaccine, a dispersible dry powder formulation.  The dry powder vaccine could be inhaled -- directly delivered to the nose or lungs to trigger an immune response at the site of infection. The dry powder formulation is not only designed to be easily administrable and temperature stable, but could also provide benefits in the type of immune responses generated, which could make the vaccine more practically and equitably available in the low-resource areas most heavily burdened by TB.  The dry powder is designed for the ability to be mass-produced, stored, and distributed to meet demand. It removes the need for injection, which eliminates needles and the need for trained medical personnel to inject the vaccine.  AAHI’s inhalable dry powder TB vaccine candidate has demonstrated encouraging results in preclinical studies. 

AAHI is dedicated to developing vaccines to protect the world’s most vulnerable populations and will continue to work toward ending the threat of TB. We are grateful to our partners Lyophilization Technology Inc., Advanced BioScience Laboratories, Saint Louis University, DF/Net Research, the University of Iowa, University of Alberta, Washington University at St. Louis, Texas Biomedical Research Institute, and the National Institute of Allergy and Infectious Disease who were delightful to work with and made these advancements towards ending TB possible.

About Tuberculosis

TB is the leading infectious killer in the world, second only to COVID-19. TB spreads when an infected person exhales small infectious particles that are inhaled by those in close proximity. TB is caused by a bacteria, Mycobacterium tuberculosis, that has been infecting humans for thousands of years. And for thousands of years, TB has proven to be difficult to control because it is often asymptomatic, or latent. Many people who carry or spread TB do not know they are infected.

Although the world has made significant progress toward controlling TB since the 1600-1800s when TB caused 25% of all deaths in Europe, TB still causes at least 1.5 million deaths every year. A shocking 25 percent of the global population is thought to be infected with either latent or active TB.  Meanwhile, the current leading TB vaccine candidate, GSK’s combination of the “M72” antigen and the “AS01E” immune-stimulating adjuvant formulation, is only 50% effective in adults three years after vaccination. It also requires refrigeration for transport, storage, and distribution, which poses a challenge in areas of the world with the highest TB incidence rate – South-East Asia, Africa, and the Western Pacific.  There is a clear need for an effective TB vaccine that is sufficiently stable to withstand extended exposure to ambient temperatures.