Author/Authors :
Brenciaglia, Marco St. George’s University School of Medicine - True Blue Campus, Grenada , Noel, Trevor P St. George’s University School of Medicine - True Blue Campus, Grenada , Fields, Paul j St. George’s University School of Medicine - True Blue Campus, Grenada , Bidaisee, Satesh St. George’s University School of Medicine - True Blue Campus, Grenada , E.Myers, Todd Naval Medical Research Center, Silver Springs, USA , Nelson, WilliamM Tetracore Inc., Rockville, USA , Venkateswaran, Neeraja Tetracore Inc., Rockville, USA , Venkateswaran, Kodumudi Omni Array Biotechnology, Rockville, USA , Parameswaran, Nishanth Omni Array Biotechnology, Rockville, USA , Bahadoor, Avi St. George’s University School of Medicine - True Blue Campus, Grenada , Yearwood, Katherine St. George’s University School of Medicine - True Blue Campus, Grenada , Mapp-Alexander, Veronica St. George’s University School of Medicine - True Blue Campus, Grenada , Mitchell, George Ministry of Health - Ministerial Complex, Grenada , LaBeaud, Desiree Stanford University - Stanford, USA
Abstract :
Background
Group A streptococcus (GAS) infections and poststreptococcal sequelae remain a health problem worldwide, which necessitates searching for an effective vaccine, while no licensed GAS vaccine is available. We have developed a divalent peptide vaccine composed of 84 amino acids to cover the main GAS serotypes (M1 and M12 streptococci) in China, and herein, we aimed to evaluate immunogenicity and safety of this vaccine.
Methods
Mice were immunized with the vaccine. ELISA, indirect bactericidal test, and immunofluorescent assay were used to study immunogenicity. GAS challenge assay was used to test the protective effect. Safety was tested by histopathological analysis.
Results
Immunized group mice (n=16) developed higher titer antibody after immunization than nonimmunized group mice (n=16) did. This antibody can deposit on the surface of GAS and promote killing of GAS, resulting in 93.1% decrease of M1 GAS and 89.5% of M12 GAS. When challenged with M1 and M12 streptococci, immunized group mice had a higher survival rate (87.5% and 75%) than nonimmunized group mice (37.5% and 25%). No autoimmune reactions were detected on organs of mice.
Conclusion
The results suggest that this vaccine shows fair immunogenicity and safety, which will lead our research on GAS vaccine into clinical trial.
