Impact of 10-and 13-valent pneumococcal conjugate vaccines on incidence of invasive pneumococcal disease in children aged under 16 years in Germany, 2009 to 2012

We assessed the impact of 10-valent and 13-valent pneumococcal vaccines (PCV10 and PCV13), which were introduced in Germany in 2009, on the incidence of meningitis and non-meningitis invasive pneumococcal disease (IPD) in children aged under 16 years in a population previously vaccinated with a sevenvalent vaccine (PCV7). Surveillance of IPD (isolation of Streptococcus pneumonia from a normally sterile body site) is based on data from two independent reporting sources: hospitals and laboratories. IPD incidence was estimated by capture-recapture analysis. Incidence rate ratios (IRRs) were calculated for 2009 and 2012, thus comparing pre-and post-PCV10 and PCV13 data. IPD incidence caused by serotypes included in PCV13 decreased in all age and diagnosis groups. A rise in non-vaccine serotype incidence was seen only in children aged under two years. The overall impact varied by age group and infection site: for meningitis IPD in children aged under 2, 2-4 and 5-15 years, incidence changed by 3% (95% CI: -31 to 52), -60% (95% CI: -81 to -17) and -9% (95% CI: -46 to 53), respectively. A more pronounced incidence reduction was observed for non-meningitis IPD: -30% (95% CI: -46 to -7), -39% (95% CI: -54 to -20) and -83% (95% CI: -89 to -73) in children aged under 2, 2-4 and 5-15 years, respectively. A higher tropism of the additional serotypes for non-meningitis IPD may be a potential explanation. The heterogeneous findings emphasise the need for rigorous surveillance

Recombinant plants provide a new approach to the production of bacterial polysaccharide for vaccines

Bacterial polysaccharides have numerous clinical or industrial uses. Recombinant plants could offer the possibility of producing bacterial polysaccharides on a large scale and free of contaminating bacterial toxins and antigens. We investigated the feasibility of this proposal by cloning and expressing the gene for the type 3 synthase (cps3S) of Streptococcus pneumoniae in Nicotinia tabacum, using the pCambia2301 vector and Agrobacterium tumefaciens-mediated gene transfer. In planta the recombinant synthase polymerised plant-derived UDP-glucose and UDP-glucuronic acid to form type 3 polysaccharide. Expression of the cps3S gene was detected by RT-PCR and production of the pneumococcal polysaccharide was detected in tobacco leaf extracts by double immunodiffusion, Western blotting and high-voltage paper electrophoresis. Because it is used a component of anti-pneumococcal vaccines, the immunogenicity of the plant-derived type 3 polysaccharide was tested. Mice immunised with extracts from recombinant plants were protected from challenge with a lethal dose of pneumococci in a model of pneumonia and the immunised mice had significantly elevated levels of serum anti-pneumococcal polysaccharide antibodies. This study provides the proof of the principle that bacterial polysaccharide can be successfully synthesised in plants and that these recombinant polysaccharides could be used as vaccines to protect against life-threatening infections

Systematic Evaluation of Serotypes Causing Invasive Pneumococcal Disease among Children Under Five: The Pneumococcal Global Serotype Project

Hope Johnson and colleagues calculate the global and regional burden of serotype-specific pneumococcal disease in children under the age of five