ORIGINAL RESEARCH
Immunological memory formed in response to administration of GamTBvac recombinant tuberculosis vaccine candidate: clinical trials in healthy volunteers
1 Laboratory of Translational Biomedicine,N. F. Gamaleya Federal Research Centre for Epidemiology and Microbiology, Moscow, Russia
2 Institute of Molecular Medicine,I. M. Sechenov First Moscow State Medical University, Moscow, Russia
3 Department of Virology, Faculty of Biology,Lomonosov Moscow State University, Moscow
Correspondence should be addressed: Denis A. Kleymenov
ul. Gamalei, d. 18, Moscow, Russia, 123098; ur.relbmar@tel00001
Funding: this work was supported by the Russian Ministry of Health and the Federal Agency for Scientific Organizations (state task no. 0574-2014-0023)
Contribution of the authors to this work: Kleymenov DA — analysis of literature, research planning, research preparation, data collection, analysis, and interpreatation, drafting of a manuscript, writing of a final version of a manuscript; Mazunina EP — analysis of literature, research planning, research preparation, data collection, analysis, and interpretation, drafting of a manuscript; Lunin VG — analysis of literature, research planning, research preparation, drafting of a manuscript; Koptev EYu, Manuilov VA — analysis of literature, research preparation, drafting of a manuscript; Gushchin VA — analysis of literature, research planning, research preparation, data analysis and interpretation, drafting of a manuscript, writing of a final version of a manuscript; Tkachuk AP — analysis of literature, research planning, research preparation, drafting of a manuscript, critical analysis of a manuscript.
So far BCG, a live attenuated Mycobacterium bovis strain remains the only available vaccine for tuberculosis prevention and control. Although BCG is effective against miliary tuberculosis and tuberculous meningitis in children, it barely protects adults and adolescents from the pulmonary form of the disease or reactivation of the latent infection. Still, its effectiveness can be increased by using recombinant booster vaccines containing both M. bovis and M. tuberculosis antigens. This article reports preliminary data on the safety and immunogenicity of a recombinant vaccine candidate, GamTBvac, developed for tuberculosis prevention. Its immunogenicity was studied in 12 volunteers. Over the course of 20 weeks following GamTBvac administration, we measured cell-mediated and humoral immune responses using interferon-gamma release assays and multiplex xMAP- based immunoassays. On day 140 after the first administration of the vaccine, 10 participants of the study (83 %) still showed a positive cellular response to all antigens contained in the vaccine. Both sense antigens CFP10 and ESAT6 induced production of IgG antibodies between days 98 and 140 of the observation. The Ag85 antigen induced a relatively weak humoral response. On the whole, the recombinant GamTBvac is safe and activates cell-mediated and humoral components of the adaptive immunity, forming immunological memory.
Keywords: tuberculosis, humoral immunity, immunological memory, cell-mediated immunity, BCG, M. bovis, M. tuberculosis, IGRA, suspension immunoassay, ESAT6, CFP10, Ag85