Quantitation and characterization of serotype 6A activation for pneumococcal conjugate vaccine by cryo-EM and SEC methods.

Pneumococcal conjugate vaccines (PCV) typically consist of capsular polysaccharides from different S. pneumoniae serotypes which are covalently attached to carrier protein. A well-established process to manufacture PCV is through activating polysaccharide by oxidation of vicinal diols to aldehydes, followed by protein conjugation via reductive amination. Polysaccharide activation is a crucial step that affects vaccine product critical attributes including conjugate size and structure. Therefore, it is highly desired to have robust analytical methods to well characterize this activation process. In this study, using pneumococcal serotype 6A as the model, we present two complimentary analytical methods for characterization of activated polysaccharide. First, a size exclusion chromatography (SEC) method was developed for quantitative measurement of polysaccharide activation levels. This SEC method demonstrated good assay characteristics on accuracy, precision and linearity. Second, a gold nanoparticle labeled cryo-electron microscopy (Cryo-EM) technique was developed to visualize activation site distribution along polysaccharide chain and provide information on activation heterogeneity. These two complimentary methods can be utilized to control polysaccharide activation process and ensure consistent delivery of conjugate vaccine products.

Immunogenicity and safety of a 14-valent pneumococcal polysaccharide conjugate vaccine (PNEUBEVAX 14™) administered to 6-8 weeks old healthy Indian Infants: A single blind, randomized, active-controlled, Phase-III study.

BACKGROUND: Introduction of pneumococcal conjugate vaccines (PCVs) reduced the number of cases of pneumococcal disease (PD). However, there is an increase in clinical and economic burden of PD from serotypes that are not part of the existing pneumococcal vaccines, particularly impacting pediatric and elder population. In addition, the regions where the PCV is not available, the disease burden remains high. In this study, immunogenicity and safety of the BE's 14-valent PCV (PNEUBEVAX 14™; BE-PCV-14) containing two additional epidemiologically important serotypes (22F and 33F) was evaluated in infants in comparison to licensed vaccine, Prevenar-13 (PCV-13). METHODS: This is a pivotal phase-3 single blind randomized active-controlled study conducted at 12 sites across India in 6-8 weeks old healthy infants at 6-10-14 weeks dosing schedule to assess immunogenic non-inferiority and safety of a candidate BE-PCV-14. In total, 1290 infants were equally randomized to receive either BE-PCV-14 or PCV-13. Solicited local reactions and systemic events, adverse events (AEs), serious AEs (SAEs), and medically attended AEs (MAAEs) were recorded. Immunogenicity was assessed by measuring anti-PnCPS (anti-pneumococcal capsular polysaccharide) IgG concentration and functional antibody titers through opsonophagocytic activity (OPA), one month after completing three dose schedule. Cross protection to serotype 6A offered by serotype 6B was also assessed in this study. FINDINGS: The safety profile of BE-PCV-14 was comparable to PCV-13 vaccine. Majority of reported AEs were mild in nature. No severe or serious AEs were reported in both the treatment groups. For the twelve common serotypes and for the additional serotypes (22F and 33F) in BE-PCV-14, NI criteria was demonstrated as defined by WHO TRS-977. Primary immunogenicity endpoint was met in terms of IgG immune responses for all 14 serotypesof BE-PCV-14. Moreover, a significant proportion of subjects (69%) seroconverted against serotype 6A, even though this antigen was not present in BE-PCV-14. This indicates that serotype 6B of BE-PCV-14 cross protects serotype 6A. BE-PCV-14 also elicited comparable serotype specific functional OPA immune responses to all the serotypes common to PCV-13. INTERPRETATIONS: BE-PCV-14 was found to be safe and induced robust and functional serotype specific immune responses to all 14 serotypes. It also elicited cross protective immune response against serotype 6B.These findings suggest that BE-PCV-14 can be safely administered to infants and achieve protection against pneumococcal disease caused by serotypes covered in the vaccine. The study was prospectively registered with clinical trial registry of India - CTRI/2020/02/023129.

Characterization of pneumococcal serotype 7F in vaccine conjugation.

Streptococcus pneumoniae is a highly invasive bacterial pathogen that can cause a range of illnesses. Pneumococcal capsular polysaccharides (CPS) are the main virulence factors that causes invasive pneumococcal disease (IPD). Pneumococcal CPS serotype 7F along with a few other serotypes is more invasive and likely to cause IPD. Therefore, 7F is a target for pneumococcal vaccine development, and is included in the two recently approved multi-valent pneumococcal conjugated vaccines, i.e. VAXNEUVANCE and PREVNAR 20.To support process and development of our 15-valent pneumococcal conjugated vaccine (PCV15), chromatographic methods have been developed for 7F polysaccharide and conjugate characterization. A size-exclusion chromatography (SEC) method with UV, light scattering and refractive index detections was employed for concentration, size and conformation analysis. A reversed-phase ultra-performance liquid chromatography (RP-UPLC) method was used for analysis of conjugate monosaccharide composition and degree of conjugation. The collective information obtained by these chromatographic analysis provided insights into the pneumococcal conjugate and conjugation process.

Immunochemical characteristics of Streptococcus pneumoniae type 3 capsular polysaccharide glycoconjugate constructs correlate with its immunogenicity in mice model.

A panel of derivatives were prepared from Streptococcus pneumoniae polysaccharide type 3 (Ps3) modified with adipic acid dihydrazide (ADH). The degree of coupling between Ps3-adh derivatives and diphtheria (DTd) or tetanus (TTd) toxoids was varied by ADH linker loading. A series of Ps3 derivatives and the resultant glycoconjugates (GC) were tested for their immunochemical activity in an ELISA. Antigenic properties of components in GCs were estimated by interaction with serotype-specific and toxin-neutralizing antibodies to confirm the preservation of native protective epitopes both of Ps3 and DTd. After immunization of mice, a correlation was established between immunochemical activity and immunogenicity of these GCs. A correlation model developed for Ps3-DTd conjugates allowed to predict the immunogenicity of similar design Ps3-TTd conjugates based on ELISA testing data. The plausibility of this prediction was confirmed by the test immunization of mice with Ps3-TTds. The proposed immunochemical approach to the assessment and control of native structural and functional antigenic elements in GCs is important for the optimization of vaccine design and is an adequate alternative to extensive physicochemical characterization for assessing immunogenicity.

Isolating polysaccharide IgG pneumococcal antibody responses by pre-adsorption of conjugate vaccine serotypes: A modified approach for the conjugate vaccine era.

BACKGROUND: Assessment of pure polysaccharide response to the 23-valent pneumococcal polysaccharide vaccine (PPV23) can be biased by previous exposure to the conjugate vaccine (PCV). We applied pre-analytical modification to the existing ELISA by pre-incubating serum with PCV. METHODS: PCV-adsorbed and non-adsorbed sera were prepared before measuring the concentration of anti-pneumococcal capsular polysaccharide (PCP) IgG antibodies by the whole pneumococcal ELISA. Paired pre and post-pneumococcal vaccination sera from 73 subjects were analyzed and the baseline anti-PCP IgG for each sample was subtracted from the post-vaccination value to measure vaccine responses. Absolute change in titers and fold changes were then compared between both methods. RESULTS: In the PCV-vaccinated group (n = 28), pre-adsorption with PCV significantly reduced the vaccine responses compared to non-adsorbed sera [median increase in anti-PCP titers: 27.55 mg/l and 45.98 mg/l, respectively]. In addition, the median fold change dropped significantly from 3.026 to 2.313. In PPV23-vaccinated immunocompetent subjects (n = 28) there was a significant difference in anti-PCP responses with PCV adsorption [median values: 73.71 mg/l without and 51.04 mg/l with adsorption]. All the antibody deficiency patients (n = 17) displayed poor PPV23 responses. Although PPV23 responsiveness was not statistically different between both methods, we have observed a trend for lower anti-PCP IgG titers in PCV-adsorbed sera compared to non-adsorbed ones. Serotype-specific IgG analysis using a multiplexed bead-based immunoassay performed on 10 paired samples confirmed that the adsorption observed is specific to PCV serotypes. CONCLUSION: Pre-analytical modification to the conventional ELISA by removing the PCV-specific serotypes may differentiate true polysaccharide response from recall response induced by previous PCV vaccination.

Quality Improvement of Capsular Polysaccharide in Streptococcus pneumoniae by Purification Process Optimization.

Streptococcus pneumoniae is the causative agent of many diseases, most notably pneumonia. Most of the currently used vaccines to protect against this pathogen employ pneumococcal capsular polysaccharides (CPSs) as antigens, but purifying CPS of sufficient quality has been challenging. A purification process for CPS comprising conventional methods such as ultrafiltration, CTAB precipitation, and chromatography was previously established; however, this method resulted in high cell wall polysaccharide (CWPS) contamination, especially for serotype 5. Thus, a better purification method that yields CPS of a higher quality is needed for vaccine development. In this study, we significantly reduced CWPS contamination in serotype 5 CPS by improving the ultrafiltration and CTAB precipitation steps. Moreover, by applying an acid precipitation process to further remove other impurities, serotype 5 CPS was obtained with a lower impurity such as decreased nucleic acid contamination. This improved method was also successfully applied to 14 other serotypes (1, 3, 4, 6A, 6B, 7F, 9V, 11A, 14, 18C, 19A, 19F, 22F, and 23F). To assess the immunogenicity of the CPS from the 15 serotypes, two sets of 15-valent pneumococcal conjugate vaccines were prepared using the previous purification method and the improved method developed here; these vaccines were administered to a rabbit model. Enzyme-linked immunosorbent assay and opsonophagocytic assay demonstrated higher immunogenicity of the conjugate vaccine prepared using CPS produced by the improved purification process.

A Japanese nationwide survey of 23-valent pneumococcal capsular polysaccharide vaccine (PPSV23) revaccination coverage rate among elderly adults aged 65 and older and physician's attitude.

In July 2017, the Japanese Association for Infectious Diseases issued guidance for the administration of the PPSV23 revaccination. Despite increasing recognition of its protective benefits, levels of PPSV23 revaccination coverage rate in Japanese elderly population are unclear at present. Here, we report the results of a survey to know PPSV23 revaccination rates among elderly patients aged 65 and older. We asked an array of questions related to PPSV23 revaccination to Elderly adults and doctors across Japan via Web-based surveys in June 2018. The sampled population consisted of 5,085 men and women aged 65 and older. The PPSV23 revaccination coverage rate was estimated by survey questions regarded vaccination counts, intervals, and vaccine type. In addition, 400 internal medicine physicians were surveyed and asked about their reasons for recommending PPSV23 revaccination to elderly patients. In total, 1,648 elderly adults had received at least one PPSV23 dose; of these, 58 had received it at least twice (revaccination coverage rate: 3.5%). The most commonly cited justification for revaccination with PPSV23 among the surveyed physicians was that the benefits of revaccination exceed the risks of revaccination. In addition, multivariate analysis showed revaccinated status was most strongly associated with recommendations from peers (e.g. spouse, family, friends) among elderly subjects. This study reports PPSV23 revaccination coverage rate among Japanese adults aged 65 and older for the first time and concludes that the coverage rate is very low.

In vitro and in vivo characterization of the interaction, proinflammatory, immunomodulatory and antigenic properties of capsular polysaccharide from Streptococcus pneumoniae serotype 1.

Pneumococcal capsular polysaccharide (PCP) is the major virulence determinant of Streptococcus pneumoniae (pneumococcus). Strains devoid of the capsule are avirulent or highly attenuated. PCP is present in soluble form and on pneumococci in infected individuals. The present study was undertaken to study the interaction of PCP from serotype 1 (PCP1) with immune cells, and its proinflammatory, immunomodulatory and antigenic properties. Binding of PCP1 to the surface of immune cells led to proinflammatory cytokine production which was not cell line or cytokine restricted. HEK293T transfectants expressing TLR1 and TLR2 produced IL-8 upon stimulation with PCP1, untransfected cells did not do so. PCP1 failed to induce TNF-α production from RAW264.7 cells when pre-incubated with a TLR2 blocking antibody. The surface binding of PCP1 was abrogated in the presence of TLR2 blocking antibody. PCP1 failed to bind TLR2 deficient RAW264.7 cells and induce TNF-α production. Unlike PCP1, alkali-treated PCP1 failed to stimulate RAW264.7 cells to produce TNF-α indicating the importance of alkali-sensitive moieties like O-acetyl groups. Alkali-treated PCP1 elicited lower anti-PCP1 antibody response. Mice experiments suggested that alkali-sensitive groups are significant target of protective antibodies in PCP1 immunized mice. Our findings demonstrate that PCP1 is an important modulator of immune response against pneumococci.

A Japanese nationwide survey of 23-valent pneumococcal capsular polysaccharide vaccine (PPSV23) coverage among patients with chronic medical condition aged 50 and older.

The 23-valent capsular polysaccharide pneumococcal vaccine (PPSV23) was introduced in Japan's routine immunization schedule October 2014. It was recommended for adults aged 65 years (including those ≥65 during the transition period), and for adults 60-64 with cardiac, renal, or respiratory dysfunction equivalent to Level 1 physical disability. Several studies have shown that patients aged 50+ with chronic medical conditions (CMC) are at elevated risk of pneumococcal infection. Nonetheless, PPSV23 vaccination rates among this population remains low. In our study, we report the results of a survey investigation into PPSV23 vaccination rates among Japanese patients aged 50+ with CMC. Patients aged 50+ comprised the patient population (n = 5,078) and internal medicine physicians comprised the doctor population (n = 400) located all over Japan were asked an array of questions relevant to PPSV23 immunization in June 2018 via Web-based surveys. PPSV23 coverages among chronic patients aged 50-59, 60-64, and 65+ years were respectively 1.3%, 2.9%, and 37.8%. The high disease-specific PPSV23 rates seen in the 65+ group was 50.0% and 49.4%, for chronic liver disease and chronic lung disease, respectively. Doctors most frequently cited a lack of municipal subsidies as justification for recommending the vaccine to patients with CMC aged 50-64 years, and deference to patients' wishes as justification for patients with CMC aged 65+. In conclusion, PPSV23 has poor coverage among Japanese adults aged 50-64 with CMC. Doctors and local authorities need to raise public awareness to improve the vaccination rate, given the high risk of pneumococcal infectious disease among patients with CMC.

Removal of cell wall polysaccharide in pneumococcal capsular polysaccharides by selective degradation via deamination.

Pneumococcal cell wall polysaccharide (C-PS), a contaminant in pneumococcal capsular polysaccharide (Pn-PS) vaccines is degraded by mild deamination of the 4-amino-2-acetamido-2,4,6-tri-deoxy-galactose (AAT) in C-PS, which was carried out by addition of 5% aqueous sodium nitrite to a solution of polysaccharide in 5% aqueous acetic acid. Glycosidic linkage and functional groups such as O-acetates, phosphodiesters, and pyruvates were preserved under the conditions. The small fragments from degraded C-PS were removed by ultrafiltration or dialysis to provide essentially C-PS free Pn-PS. Because of the presence of AAT in its structure the deamination is not suitable for the purification of type 1 Pn-PS. Meanwhile, the mass and NMR spectroscopic analysis on the deamination products suggests that both type 1 Pn-PS and C-PS degraded following a major pathway of 5,4-hydride shift, cleavage of AAT O5-C1 bond, C1 hemiacetal formation, and its hydrolysis to release neighboring GalA- in type 1 Pn-PS and GalNAc(6-O-PCho)- in C-PS.

Complementary Role of CD4+ T Cells in Response to Pneumococcal Polysaccharide Vaccines in Humans.

Bacterial pathogens expressing capsular polysaccharides are common causes of mucosal infections (pneumonia, intestinal), as well as often fatal, invasive infections (meningitis, bloodstream infections) in children and adults worldwide. These chemically simple but structurally complex carbohydrate structures on the bacterial surface confer resistance to recognition and clearance by the immune system through a range of mechanisms. Such recognition of capsular polysaccharides may be reduced by their limited ability to directly stimulate B cells and the T cells that may facilitate these humoral responses. The capsules may promote the evasion of complement deposition and activation and may sterically shield the recognition of other subjacent protein antigens by innate factors. Antibodies to capsular polysaccharides, elicited by infection and vaccines, may overcome these obstacles and facilitate bacterial agglutination at mucosal surfaces, as well as the opsonization and clearance of these organisms in tissues and the systemic compartment. However, the immunogenicity of these antigens may be limited by their lack of direct recognition by T cells ("T-independent" antigens) and their restricted ability to generate effective memory responses. In this review, we consider the mechanisms by which polysaccharides may initiate B cell responses and specific antibody responses and the role of T cells, particularly CD4+ follicular helper (TFH) cells to support this process. In addition, we also consider more recent counterintuitive data that capsular polysaccharides themselves may bind major histocompatibility antigen HLA class II to provide a more physiologic mechanism of T cell enhancement of B cell responses to capsular polysaccharides. Defining the contributions of T cells in the generation of effective humoral responses to the capsular polysaccharides will have important implications for understanding and translating this immunobiology for the development of more effective vaccines, to prevent the morbidity and mortality associated with these common mucosal and invasive pathogens in populations at risk.

Improving pneumococcal vaccine uptake in veterans with chronic lymphocytic leukemia through a virtual clinic.

Through a "virtual clinic," we used the electronic medical record to identify and intervene upon patients with chronic lymphocytic leukemia (cll) who were not current for pneumococcal vaccines. Within 180 days, 100/160 patients (62%) received the recommended pneumococcal vaccine. A virtual clinic may improve vaccination rates among high-risk patient populations.

A virtual clinic improves pneumococcal vaccination coverage among patients living with HIV at a Veterans Affairs Medical Center.

People living with the human immunodeficiency virus (HIV) should receive pneumococcal vaccinations as part of their routine health maintenance. Our goal was to create a "virtual clinic" to help increase rates of pneumococcal vaccination among people living with HIV without adding substantially to the workload of primary providers. We used administrative data from our Veterans Affairs (VA) medical center to identify a cohort of veterans living with HIV who were not current with either the 13-valent pneumococcal conjugate vaccine (PCV13), the 23-valent pneumococcal polysaccharide vaccine (PPSV23) or both. We enrolled these individuals (n = 99) into a virtual clinic, notified providers via the electronic medical record and mailed letters to the veterans recommending they receive a pneumococcal vaccine. We also wrote orders for the appropriate pneumococcal vaccine that expired after 90 days. Among the virtual clinic cohort, 38% (38/99) of patients received the recommended vaccine within 180 days. Concurrent with our intervention, the Veterans Health Administration deployed a system-wide pneumococcal vaccine clinical reminder that incorporated recent PCV13 recommendations. To discern any effect of the virtual clinic beyond that of the clinical reminder, we compared the rate of PCV13 vaccinations among all HIV-positive veterans at our institution to the equivalent population from 2 other VA medical centers in Ohio. With consideration of the VHA's system-wide clinical reminder, the proportion of HIV-positive patients who received PCV13 in the first 90 days following the virtual clinic intervention was greater at our facility compared to another Ohio VA medical center (P < 0.05). The virtual clinic improved the pneumococcal vaccine coverage among HIV-positive veterans. These outcomes suggest that even in conjunction with a system-wide clinical reminder, the virtual clinic strategy improves vaccination rates among a high-risk population.

Concentration of anti-pneumococcal capsular polysaccharide IgM, IgG and IgA specific antibodies in adult blood donors.

OBJECTIVES: Anti-pneumococcal capsular polysaccharide (PCP) IgM, IgG and IgA ELISAs have been developed to aid assessment of the adaptive immune system. The relationship between the concentrations of PCP IgM, IgG, and IgA was investigated. DESIGN AND METHODS: The concentrations of PCP IgM, IgG, and IgA were measured in sera obtained from 231 adult blood donors. RESULTS: Concentrations of each isotype were not normally distributed. The median concentration for PCP IgM was 54 U/mL (range 37-75 U/mL), IgG 40 mg/L (range 26-79 mg/L) and IgA 21 U/mL (range 13-44 U/mL). The median PCP IgM titres decreased with age and were significantly lower in patients aged 81-90 years compared to those aged 18-80 years. By contrast, there was a significantly higher median serum PCP IgG titre in the 61-90 years group compared to those aged 18-60 years and a significantly higher median serum PCP IgA titre in the 51-90 years group compared to those aged 18-50 years. The correlation between PCP IgG and IgA was more significant than between IgM and IgA and between IgM and IgG. Correlation of PCP IgA and IgM concentrations identified four phenotypes: high PCP IgM and IgA; high PCP IgM only; high PCP IgA only; and low PCP IgM and IgA. A significant number of individuals with a PCP IgG concentration >50 mg/L had low PCP IgA and IgM concentrations. CONCLUSION: The additional measurement of PCP IgA and PCP IgM, alongside PCP IgG, in individuals investigated for a compromised immune system may provide a more detailed antibody profile.

Specific antibody deficiency with normal immunoglobulin concentration in children with recurrent respiratory infections.

BACKGROUND: Response to polysaccharide antigens is a test to evaluate the immunological competence of children with recurrent respiratory infections (RRI) of unknown cause and no other immune system abnormality. In order to detect specific antibody deficiency (SAD), a group of children with RRI without other immunodeficiency were prospectively studied. METHODS: We included 20 children (12 male), age range 3-14 years, with six or more annual episodes of respiratory infections (RI); one or more monthly episodes of RI during the winter months; or three or more annual episodes of lower RI. The children were immunised with 23-valent polysaccharide anti-pneumococcal vaccine, and ELISA was used to measure anti-polysaccharide IgG antibody levels for 10 pneumococcal serotypes at baseline (T0), and 45 days (T1) and one year post-immunisation (T2). Post-immunisation response above 1.3 µg/ml for more than 50% of the serotypes was considered normal for children 2-5 years, and for more than 70% of the serotypes in children older than 5 years. RESULTS: At T1 19/20 children showed a normal response for their age, and only one patient showed a deficient response, suggestive of classic moderate SAD. At T2, 8/20 patients showed deficient responses, suggestive of impaired persistence of specific antibodies. There was a noteworthy association between deficient response and asthma and allergic rhinitis. CONCLUSIONS: We propose first ruling out local or systemic causes, then performing serum immunoglobulin IgM, IgG, IgA, IgE and IgG subclass levels, and finally measuring response to polysaccharide pneumococcal antigens for detection of SAD.

Immunogenicity and safety of 23-valent pneumococcal polysaccharide vaccine as a booster dose in 12- to 18-month-old children primed with 3 doses of 7-valent pneumococcal conjugate vaccine.

The current study examined the safety and immunogenicity of 23-valent pneumococcal capsular polysaccharide vaccine (Pneumo23(®) [PPV23], Sanofi Pasteur) as a booster dose in 12- to 18-month-old children primed with heptavalent pneumococcal vaccine (PCV7; Prevnar(®), Pfizer). This was a randomized, observer-blinded, 2-arm, controlled, multicenter phase III study performed in Thailand to assess and describe the immunogenicity and safety of PPV23 as a booster dose in children who had received the 3 primary doses of PCV7, the pneumococcal vaccine available during the study period. Children primed with 3 doses of PCV7 were randomized 1:1 to receive a booster immunization with PPV23 or PCV7. Pneumococcal antibody concentrations were measured by enzyme-linked immunosorbent assay and functional antibody levels by multiplex opsonophagocytosis assay on day 30. A total of 339 children were enrolled. Geometric mean serum antibody concentrations against serotypes common to PCV7 and PPV23 (4, 6B, 9V, 14, 18C, 19F, and 23F) increased in both groups but they were higher for serotypes 4, 9V, 18C, and 19F in the PPV23 group. Opsonization indices increased in both groups for all measured serotypes (1, 6B, 14, 19A, and 23F) and were higher for serotypes 6B, 14, and 23F in the PCV7 group and for serotypes 1 and 19A in PPV23 group. Solicited reactions and unsolicited adverse events were similar in the 2 groups and generally mild and transient. No treatment-related serious adverse events were reported. These results confirm that boosting with PPV23 is immunogenic and well tolerated in healthy toddlers primed with PCV7.

Additive preventive effect of influenza and pneumococcal vaccines in the elderly: results of a large cohort study.

Elderly people are at increased risk of influenza and pneumococcal diseases. Influenza increases clinical pneumococcal disease incidence. Pneumococcal vaccination could therefore be a supplement to influenza vaccination. This study evaluated all-cause mortality and antibiotic consumption according to elderly people's influenza and pneumococcal vaccination status. Its goal was to demonstrate that vaccination with both Influenza and pneumococcal vaccines decrease all-cause mortality and antibiotic consumption. From 2004-10-01 to 2004-12-31 (3 mo), elderly people (≥ 65 y) who lived in the Gard department (South of France) were offered both vaccinations. Among the 68,897 subjects followed-up one year after this vaccination campaign, 21,303 (30.9%) were vaccinated with both vaccines, 18,651 (27.1%) with influenza vaccine alone, 3,769 (5.5%) with pneumococcal vaccine alone; 25,174 (36.5%) subjects were unvaccinated. Mortality rate (per 1,000 inhabitants-year) adjusted on gender, age and prior underlying chronic disease was 17.9 (95% CI: 16.3-19.6), 20.8 (19.0-22.8), 22.5 (19.0-26.6) and 24.7 (22.7-26.8), respectively. It was 42.1 (38.8-45.8) in elderly people with underlying chronic disease who received both vaccines vs. 58.1 (53.7-62.9) in unvaccinated elderly people. The decrease in mortality rate was 27.0% (20.0-34.0) in subjects who received both vaccines and 16.0% (6.0-24.0) in those who received influenza vaccine. No significant reduction in mortality rate was seen with the pneumococcal vaccine alone. Influenza and/or pneumococcal vaccinations did not decrease antibiotic consumption that drastically increases during the winter period. An additive effect was observed in the prevention of all-cause mortality with influenza and pneumococcal vaccines given together in elderly people, including in those with underlying chronic disease.

The difference of anti-pneumococcal capsular polysaccharide IgG levels in plasma of asthmatic and non-asthmatic children / 临床儿科杂志

Objectives To explore the humoral immunologic mechanisms of the susceptibility to invasive pneumococcal diseases (IPD) in asthmatic children. Methods Plasma samples were collected from 43 asthmatic and 20 non-asthmatic chil-dren. Anit-pneumococcal capsular polysaccharide (PPS)-IgG concentrations were measured by enzyme-linked immunosorbent assays. Results The mean concentrations of anti-PPS 14, 19A and 23F-IgG were signiifcantly higher in asthmatic children than in non-asthmatic children (P<0.05). The ratios of the asthmatic children who had anti-PPS 14, 19A and 23F-IgG concentrations higher than the protective antibody level (≥0.2 μg/ml ) were 100%for all the serotypes. Conclusions The immune responses of producing anti-PPS IgG to defense IPD were normal in asthmatic children. Asthmatic children may be more susceptive to pneumococcal infection or colonization than non-asthmatic children.

Structure and molar mass analysis of pneumococcal capsular polysaccharides by 1 H NMR and HPSEC-MALLS / 中华微生物学和免疫学杂志

Objective To analyze the structures and molecular weight distributions of the capsular polysaccharides from 6 serotypes of pneumococcus .Methods The structures of pneumococcal capsular pol-ysaccharides of 6 serotypes were analyzed by 1 H nuclear magnetic resonance ( NMR) .Chemical shifts of all characteristic protons were investigated to analyze polysaccharide integrity and inter -assay consistency .High performance size exclusion chromatography-multi angle laser light scattering ( HPSEC-MALLS) was used to measure the molecular weights .Results The chemical shifts of all characteristic protons of the pneumococ-cal capsular polysaccharides of 6 serotypes were consistent with the standard chemical shift .The weight-aver-age molecular mass of the pneumococcal capsular polysaccharides ranged from 7.182×104 g/mol(for serotype 19A) to 1.273×106 g/mol(for serotype 9V)examined by HPSEC-MALLS.Conclusion The structures and molecular weight distributions of pneumococcal capsular polysaccharides could be rapidly and effectively ana -lyzed by 1 H NMR and HPSEC-MALLS.Moreover, C-PS and acetate contained in capsular polysaccharides could also be detected .HPSEC-MALLS is an applicable method for the quantitative analysis of molar mass distributions in different serotypes of pneumococcal capsular polysaccharides . Although 1 H NMR and HPSEC-MALLS have been accepted as the quality control measurements by WHO , to use them as the re-placements of the traditional QC method still needs further investigation .