The effect of age on the response to the pneumococcal polysaccharide vaccine

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is a leading cause of morbidity and mortality in the elderly. To prevent invasive pneumococcal diseases, the 23-valent pneumococcal polysaccharide vaccine (PPV) is recommended in subjects over 65 years of age. Although it has been reported to provide approximately 50-80% protection against invasive disease in the general elderly population, there is still controversy as to the effectiveness of the PPV in the elderly.</p> <p>Methods</p> <p>To evaluate the immune response to the pneumococcal polysaccharide vaccine in the elderly, samples from young adults and elderly were obtained before and one month after vaccination. The quantitative and qualitative response to the vaccine were measured by the ELISA and opsonophagocytic killing assay for eight vaccine type serotypes (4, 6B, 9V, 14, 18C, 19A, 19F, 23F) and one vaccine-related serotype (6A).</p> <p>Results</p> <p>The response to the pneumococcal polysaccharide vaccine showed a similar response between adults and elderly when evaluated by the ELISA, however the functional activity of the antibodies elicited after vaccination were lower in the elderly group for more than half of the serotypes evaluated. In comparison of the antibody needed for 1:8 opsonic titer, more antibodies were needed in the elderly for serotypes Pn 4, 19F, 23F and 6A, suggesting the functional activity of antibody detected by the ELISA was lower in the elderly compared with the adult group for these serotypes. As for subjects with an opsonic titer <8 after vaccination, only one subject each for serotypes Pn 4, 9V and 6A were found in the adult group. However, up to 10 (30.3%) of the subjects did not show opsonic activity after vaccination in the elderly group for serotypes Pn 4, 9V, 14, 19A and 6A.</p> <p>Conclusions</p> <p>Although the amount of antibodies elicited were similar between the two age groups, distinct differences in function were noted. This report highlights the importance of a quantitative and qualitative evaluation of the immunogenic response to the PPV in the elderly age group.</p> <p>Trial registration</p> <p>This trial is registered with Clinical trials.gov. Registration number NCT00964769</p

Facile green synthesis of oxygen-functionalized carbon nano-onion from lignin and biochar and its application in high-performance polylactic acid

Carbon nano-onion (CNO) is a new class of carbon nanomaterials with various applications such as electronics, photovoltaics, energy storage, biosensing, biomedicine, and catalysts. However, its widespread applications are hindered due to the high costs associated with hydrocarbon precursors and synthesis conditions involving hazardous chemicals, catalysts, non-atmospheric pressures, and prolonged processing time at high temperatures. Herein, we report a joule heating-based synthesis of oxygen-functionalized low-cost CNO using biomass residues without catalysts, chemicals, and solvents. It shows that while the crystalline structure and surface functional groups of the CNO are controllable, CNO with similar particle sizes (33–36 nm) and electrical conductivity (between 3.73 and 3.95 S/m) could be produced using lignins and biochar. The CNO also demonstrated excellent dispersibility in common solvents, attributed to their functional groups. When a new application of CNO as polymer additives was explored, 0.5% CNO could increase the tensile strength and modulus of polylactic acid (PLA) by 43.7% and 128.4%, flexural strength and modulus by 9.4% and 20%, and impact strength by 60.4%. Adding 0.5% CNO also increased the glass transition temperature and the thermal decomposition temperature of PLA by 6.3 and 13.7 °C, reducing oxygen and water vapor permeability by 67.4% and 48.4%. The comparison showed that the oxygen-functionalized CNO additive is superior to other nanocarbons in improving PLA performance. The energy consumption for synthesizing CNO from biochar was 15.6 MJ/kg, providing an attractive pathway to obtain low-cost green CNO for broad applications.This is a manuscript of an article published as Razzaq MEA, Luo Y, Forrester M, Ignacio MCCD, Cochran E, Vorst K, Bai X, Facile green synthesis of oxygen-functionalized carbon nano-onion from lignin and biochar and its application in high-performance polylactic acid, Journal of Cleaner Production (2023). doi: https:// doi.org/10.1016/j.jclepro.2023.139361. CC BY-NC-ND. © 2023 Elsevier Ltd