New tuberculosis skin test

SSI is developing a new and improved skin test to diagnose M. Tuberculosis infections, and has achieved excellent results to date

Current diagnostic tests for detecting M. tuberculosis infections include Tuberculin Skin Test (TST) and Interferon gamma release assays (IGRAs). Both systems have specific advantages as well as specific disadvantages. The TST has proved its value for decades and benefits from the low-tech procedure, resulting in low cost and excellent ease of use. The more recently developed IGRAs have their major advantage in their improved specificity in BCG vaccinated populations, but require laboratory facilities.

SSI's new skin test, C-Tb, combines the strengths and advantages of both technologies; the low cost and ease of use of the TST, and the high specificity of the IGRAs systems.

Thus, C-Tb is expected to be able to diagnose a M. tuberculosis infection regardless of prior BCG vaccination, in a simple well-known procedure, which will require no laboratory facilities and may be quickly and easily implemented at any site.

The C-Tb will be applicable in various clinical situations where a diagnosis of M. tuberculosis infection is needed:

• Contact tracing in relation to known TB cases
• Serial testing of health care workers
• Screening before initiation of immune suppressing treatment
• Screening of individuals with increased risk of TB for any reason
• TB diagnosis in young children where diagnosis otherwise is difficult

During the last 10 years, C-Tb has been investigated in a comprehensive clinical development program enrolling more than 3,000 participants, including children and people living with HIV. Two phase III clinical trials have been completed with very convincing results, and SSI is currently preparing a registration file for submission to the EMA.

Results from one of the Phase III trials were recently published in Lancet Respiratory Medicine.

Morten Ruhwald, MD, PhD
Head of section, Human Immunology
Infectious Disease Immunology
Center for Vaccine Research
Phone: +45 3268 3940



• Phase I clinical trial
o     First-in-Man Open Clinical Trial of a Combined rdESAT-6 and rCFP-10 Tuberculosis Specific Skin Test Reagent
o     Double-blind randomized Phase I study comparing rdESAT-6 to tuberculin as skin test reagent in the diagnosis of tuberculosis infection
• Phase II clinical trial
o     Randomised Clinical Trial Investigating the Specificity of a Novel Skin Test (C-Tb) for Diagnosis of M. tuberculosis Infection
o     Sensitivity of C-Tb: a novel RD-1-specific skin test for the diagnosis of tuberculosis infection
• Phase III clinical trial
o S    afety and efficacy of the C-Tb skin test to diagnose Mycobacterium tuberculosis infection, compared with an interferon γ release assay and the tuberculin skin test: a phase 3, double-blind, randomised, controlled trial

Business Development

SSI is seeking partners for commercialization of C-Tb
SSI is seeking regional or national partners to commercialize C-Tb in all parts of the world. Please contact SSI if you are interested in becoming a partner.

Lars Nørgaard
Business Development Manager
Statens Serum Institut
Phone: +45 4075 3209


Last revised 15 September 2017


Division of Vaccine
Dept. of Infectious Diseases Immunology
Søren Tetens Hoff
Research Scientist, MD, PhD
Tel: +45 3268 3496