Browsing by Author "Good M.F."
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Item Evaluation of safety and immunogenicity of a group a streptococcus vaccine candidate (mj8vax) in a randomized clinical trial.(2018-07-10) Sekuloski S.; Batzloff M.R.; Griffin P.; Parsonage W.; Elliott S.; Hartas J.; O'Rourke P.; Marquart L.; Pandey M.; Rubin F.A.; Carapetis J.; McCarthy J.; Good M.F.Background Group A streptococcus (GAS) is a serious human pathogen that affects people of different ages and socio-economic levels. Although vaccination is potentially one of the most effective methods to control GAS infection and its sequelae, few prototype vaccines have been investigated in humans. In this study, we report the safety and immunogenicity of a novel acetylated peptide-protein conjugate vaccine candidate MJ8VAX (J8-DT), when delivered intramuscularly to healthy adults. Methods A randomized, double-blinded, controlled Phase I clinical trial was conducted in 10 healthy adult participants. Participants were randomized 4:1 to receive the vaccine candidate (N = 8) or placebo (N = 2). A single dose of the vaccine candidate (MJ8VAX), contained 50 mug of peptide conjugate (J8-DT) adsorbed onto aluminium hydroxide and re-suspended in PBS in a total volume of 0.5 mL. Safety of the vaccine candidate was assessed by monitoring local and systemic adverse reactions following intramuscular administration. The immunogenicity of the vaccine was assessed by measuring the levels of peptide (anti-J8) and toxoid carrier (anti-DT)-specific antibodies in serum samples. Results No serious adverse events were reported over 12 months of study. A total of 13 adverse events (AEs) were recorded, two of which were assessed to be associated with the vaccine. Both were mild in severity. No local reactogenicity was recorded in any of the participants. MJ8VAX was shown to be immunogenic, with increase in vaccine-specific antibodies in the participants who received the vaccine. The maximum level of vaccine-specific antibodies was detected at 28 days post immunization. The level of these antibodies decreased with time during follow-up. Participants who received the vaccine also had a corresponding increase in anti-DT serum antibodies. Conclusions Intramuscular administration of MJ8VAX was demonstrated to be safe and immunogenic. The presence of DT in the vaccine formulation resulted in a boost in the level of anti-DT antibodies.Copyright © 2018 Sekuloski et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Item Prospecting for new group a streptococcal vaccine candidates.(2004-08-13) McMillan D.J.; Davies M.R.; Browning C.L.; Good M.F.; Sriprakash K.S.Background & objectives: Most group A streptococcal (GAS) vaccine strategies focused on the surface M protein of the GAS. However, vaccine based on M protein have some drawbacks. In the present study, we used two approaches to identify new proteins and peptides that may have utility as vaccine candidates. Method(s): A whole gel elution procedure was used to separate GAS surface antigens into 9 size fractionated pools. Mice were vaccinated with each pool and antibody titre, opsonic ability and protective capacity measured. In an alternative approach BioInformatics was used to identify putative GAS surface proteins. Peptides from within these proteins were then selected on the basis of predicted antigenicity or location. These peptides were conjugated to keyhole lymphocyanin (KLH) and immunogenicity measured in a mouse model. Result(s): One pool of GAS surface proteins (approximately 29kDa) induced antibodies that were both opsonic and potentially protective. Immunoflourescent microscopy demonstrated that these antibodies bound to the surface of M1 GAS. Amino acid sequencing subsequently identified superoxide dismutase as the major antigen in this pool. A BioInformatic search of the M1 GAS genome and subsequent analysis identified several peptides that fulfilled criteria as potential vaccine candidates. Each peptide when conjugated to KLH was able to induce a strong antibody response. Interpretation & conclusion: Several new antigens were identified that may have potential as vaccine targets. A future GAS vaccine may have multiple peptide epitopes, providing protection against multiple GAS strains.