Journal of Vaccines & Vaccination

Immunogenicity and protective effi cacy of oral multi-serotype OMVs Shigella vaccine

International Conference & Exhibition on Vaccines & Vaccination

22-24 Nov 2011 Philadelphia Airport Marriott, USA

Hemanta Koley, Soma Mitra1Soumik Barman, Dhira rani Saha and Santa Sabuj Das

Accepted Abstracts: J Vaccines Vaccin

Abstract:

Bacillary dysentery caused by Shigella species, is a major cause of infant morbidity and mortality in developed as well as in developing countries. At present, only antibiotic therapy is available for treatment of shigellosis. Unfortunately, due to the global emergence of multidrug resistance, the choice of antimicrobial agents for treating shigellosis is very limited and we are approaching where the shigellosis can become an untreatable disease because of lake of an eff ective antibiotic. Th erefore, the possibilities of other preventive measures such as anti- dysentery vaccines have attracted increasing attention in this fi eld. Various trials of several candidates� vaccine are being done in diff erent parts of the world, but till date no suitable Shigella vaccine is available for public health use. Th ere are diff erent serotypes of Shigella species and their distribution varies between endemic geographical regions. Th e immune response against Shigella species are serotype-specific, so current immunization strategies have required the administration of multiple vaccine strains to provide protection against multiple serotypes. In our study, we evaluated the protective effi cacy and immune response of cocktailed outer membrane vesicles of multiple serotypes of six Shigella strains ( S. dysenteriae 1, S. fl exneri 2a, S. fl exneri 3a, S. fl exneri 6, and S. sonnei ) in mice model and guineapig model. Th e protective effi cacy aft er oral immunization with four doses (0, 14 th & 28 th and 35 th Day) of 50 ug OMVs of Shigella strain was examined . T he protection following challenge was 100% protection in the immunized group where as the unimmunized group of animals developed dysentery. Serum IgG and IgA titers showed exponential rise during oral immunization. Histology of the colonic biopsy samples, immunoblot assays against whole cell lysate, lypopolysaccharide and outer membrane protein strongly supported the mounting of a vigourous immunune response following oral immunization. Multi-serotype OMVs Shigella cocktail antigens could be a promising vaccine candidate for shigellosis in the future.

Biography :

Dr. Hemanta Koley, MS, Ph.D, Scientist C, Division of Bacteriology, After completion of his Master degree in Physiology from University College of Science & Technology, Calcutta University, he joined in National institute of Cholera and Enteric Diseases, Beliaghata, Calcutta for his Ph. D. In 1996, he joined as Associate Professor in Dept. Physiology, College of Medical Sciences-Nepal, where he devoted entire heartily in teaching medical students till 2001. In the mean time Dr. Koley got opportunity for Post Doctoral research at Dept of Physiology, Rutgers-The State University of New Jersey, New Brunswick, USA. After completion of one year in Rutgers University, Dr. Koley moved to Boston, joined in Gastroenterology Section, Harvard Medical School as Research Associate. His present research interest is to understand signal transduction pathways in immune and in fl ammatory cells during diarrhoea and also to study the nature of protection against diarrhoeal pathogens like Vibrio cholerae and Shigella in different animal model. He has published 18 original papers and 12 abstracts in his credit. He has secured patent for a process for the preparation of Cholera Vaccine-VA1.3 (European Patent Of fi ce; Patent No.- 97309957.5-2105 on 19/05/98). Dr. Koley received Young Scientist Award in IUPS, August 26-31, 2001