Such classification resulted in datasets of 98 pre-vaccination ABTs and 74 WCV antigens, in a manner that was consistent between these groupings

Such classification resulted in datasets of 98 pre-vaccination ABTs and 74 WCV antigens, in a manner that was consistent between these groupings. == Acknowledgements == We thank the volunteers of the Phase I trial ofS. and meningitis, killing around a million people each year. Vaccines now exist to protect young children against these diseases, but they are expensive and do KC01 not work against all the strains of the bacteria. This is because these shots train the bodys immune system to recognize and attack the bacteriums capsule, a layer of sugars that surrounds CXCL5 the microbe and is often different between strains. One possible solution could be a cheap, whole cell vaccine. These injections expose the body to genetically modifiedS. pneumoniaethat do not carry the capsule. Such treatment has now been tested in a small number of people during a clinical trial. Here, Campo et al. use a technique known as panproteome array to scan samples collected during this trial, and identify which elements the body learns to recognize when it is exposed to the genetically manipulated strain ofS. pneumoniae. The results show that when volunteers receive this vaccine, their body targets proteins that the capsule normally shields from the immune system. Many of these proteins are very similar across all strains ofS. pneumoniae, which means that the whole cell vaccine could potentially better protect against a broad spectrum of bacteria. However, further studies are needed to assess whether this is the case, especially in infants. == Introduction == Streptococcus pneumoniae(the pneumococcus), commonly carried in the nasopharynx, is an important respiratory pathogen capable of causing pneumonia, bacteraemia and meningitis. The earliest recorded pneumococcal vaccinations consisted of two doses of heat-killed pneumococci cultured from the sputum of pneumonia patients, which resulted in limited protection against pneumococcal infections for a few months after inoculation (Maynard, 1915). Later pneumococcal vaccines used purified capsule polysaccharides, of which there are almost 100 immunologically distinguishable variants (Bentley et al., 2006), termed serotypes. These formulations expanded from a bivalent formulation in the 1930s (Ekwurzel et al., 1938) to include 23 capsular polysaccharides by the 1980s (Mufson et al., 1985). Such formulations afford little protection to infants, however, as polysaccharides are T-cell-independent antigens that are not efficiently recognised by the immature adaptive immune system (Stein, 1992). Therefore, the most commonly used pneumococcal vaccines at present are protein-polysaccharide conjugate vaccines (PCVs), currently containing up to 13 different polysaccharides, each attached to a carrier KC01 protein (Nunes and Madhi, 2011). These vaccines elicit protective immune responses, even in young children, which prevent nasopharyngeal carriage as well as disease (Lee et al., 2014). The intrinsic disadvantage of PCVs is the limited number of serotypes against which they provide protection, resulting in serotype replacement disease that reduces their impact (Weinberger et al., 2011). The further expansion of their valency is limited by the complexity of their manufacture, which also makes them costly (Miller et al., 2011;Ray, 2002). Therefore, efforts have continued to develop alternative vaccines that are cheaper, generate T-cell-dependent responses to non-capsular antigens, and afford protection against all pneumococci. Whole cell-based vaccines (WCVs) present a possible solution, as they can be relatively inexpensively manufactured and present an almost full complement of antigens to the recipients immune system. Rather than the historical precedent of killed clinical isolates, the WCV used in this study is a specifically engineered version of the unencapsulated strainS. pneumoniaeRM200 (Lu et al., 2010b). A randomised double-blind phase I safety and immunogenicity trial of this WCV in 42 healthy U.S. adults was designed KC01 to compare four cohorts (Figure 1). One received placebo saline injections, while the other three received 100 g, 300 g or 600 g.