• Infection and chemotherapy
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• v.50 no.4
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• pp.328-339
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• 2018

Background: Pneumococcal disease is a major cause of morbidity and mortality worldwide, especially in patients with comorbidities and advanced age. This study evaluated trends in epidemiology of adult pneumococcal disease in Crete, Greece, by identifying serotype distribution and antimicrobial resistance of consecutive Streptococcus pneumoniae strains isolated from adults during an 8-year time period (2009-2016) and the indirect effect of the infant pneumococcal higher-valent conjugate vaccines 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13). Materials and Methods: Antimicrobial susceptibility was performed by E-test and serotyping by Quellung reaction. Multidrug resistance (MDR) was defined as non-susceptibility to penicillin (PNSP) combined with resistance to ${\geq}2$ non-${\beta}$-lactam antimicrobials. Results: A total of 135 S. pneumoniae strains were isolated from adults during the study period. Twenty-one serotypes were identified with 17F, 15A, 3, 19A, and 11A, being the most common. The coverage rates of PCV10, and PCV13 were 17.8% and 37.8%, respectively. PCV13 serotypes decreased significantly from 68.4% in 2009 to 8.3% in 2016 (P = 0.002). The most important emerging non-PCV13 serotypes were 17F, 15A, and 11A, with 15A being strongly associated with antimicrobial resistance and MDR. Among all study isolates, penicillin-resistant and MDR strains represented 7.4% and 14.1%, respectively. Predominant PNSP serotypes were 19A (21.7%), 11A (17.4%), and 15A (17.4%). Erythromycin, clindamycin, tetracycline, trimethoprim-sulfamethoxazole, and levofloxacin resistant rates were 30.4%, 15.6%, 16.3%, 16.3%, and 1.5%, respectively. Conclusion: Although pneumococcal disease continues to be a health burden in adults in Crete, our study reveals a herd protection effect of the infant pneumococcal higher-valent conjugate vaccination. Surveillance of changes in serotype distribution and antimicrobial resistance among pneumococcal isolates are necessary to guide optimal prevention and treatment strategies.

• YAKHAK HOEJI
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• v.48 no.6
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• pp.345-351
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• 2004

ln the present work to determine effect of a Streptococcus pneumoniae conjugate vaccine, S.pneumoniae capsule attached to the surface protein (JY-Pol) was ex amined. This JY-Pol contained approximately 92% and 6% carbohydrate and protein, respectively. Gel electrophoresis revealed the presence of the surface protein in the JY-Pol. By the double immunodiffusion and isotyping ELISA analyses, administration of JY-Pol that was adsorbed to alum adjuvant (JY-Pol/Alum) into mice induced IgM, IgG, and IgA specific for the S.pneumoniae capsule. The ATCC capsular polysaccharide adsorbed to alum (ATCC-Pol/Alum) provoked only IgM in mice. In survival tests, mice that were immunized with the JY-Pol/Alum before intravenous challenge with live S.pneumoniae survived entire period of 46 day-observation, whereas all mice that received ATCC-Pol/Alum or only diluent instead of the vaccination died within 5 and 12 days, respectively. Results from footpad-edema test showed that JY-Pol/Alum formula provoked the cellular immunity as determined by swelling of the mouse footpad. These data indicate that the naturally conjugated JY- Pol enhances resistance of mice against disseminated pneumococcal disease due to S.pneumoniae by both humoral and cellular immune responses.

• Clinical and Experimental Pediatrics
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• v.54 no.4
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• pp.163-168
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• 2011

Purpose: The purpose of this study was to evaluate the immune response to serotype 19A in children aged 12-23 months after immunization of the 19F containing 7-valent pneumococcal conjugate vaccine (PCV7). Methods: Blood samples from a total of 45 subjects (age 12-23 months) were included in the study. Subjects were categorized according to immunization status into three groups as follows: 18 subjects with 3 primary doses and 1 booster dose of PCV7 (booster group), 21 subjects with 3 primary doses before 12 months of age (primary group), and 6 subjects with no vaccination history of PCV7 (control group). An ELISA and opsonophagocytic killing assay (OPKA) was done to evaluate the immune responses against serotypes 19F and 19A. Results: According to the ELISA, all subjects had antibody titers ${\geq}0.35{\mu}g/mL$ for serotypes 19F and 19A in the booster and primary group and 83.0% and 66.7% in the control group, respectively. According to the OPKA, subjects with opsonic activity (${\geq}20$) against serotypes 19F and 19A were 100% and 61.1% of the subjects in the booster group and 66.7% and 19.0% in the primary group, respectively. No subjects in the control group had opsonic antibodies against both serotypes. Conclusion: In conclusion, in children 12-23 months age who were previously vaccinated with PCV7, a cross-reactive immune response is elicited against serotype 19A after a primary series of 3 doses in a small proportion of subjects, and this response is amplified after booster vaccination.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.622-628
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• 2008

Purpose : The purpose of this study was to evaluate the immunogenicity of the booster immunization with pneumococcal conjugate vaccine in Korean children. Methods : Thirty-nine children aged 12-23 months who visited Kangnam CHA Hospital between September 2006 and December 2006 were enrolled. The children were divided into primary and booster groups depending on their vaccination status for the 7-valent pneumococcal conjugate vaccine. The anti-pneumococcal antibody levels of each serotype included in the vaccine (4, 6B, 9V, 14, 18C, 19F, 23F) were determined by third-generation ELISA. Results : The geometric mean titer (GMT) of antibodies to each pneumococcal serotype in the booster group was higher than in the primary group (P<.05). The percentage of subjects with pneumococcal antibodies ${\geq}0.35{\mu}g/mL$ was 90.5-100% for all serotypes in both the primary and booster groups. The percentage of subjects with pneumococcal antibodies ${\geq}1.0g/mL$ in the booster group was 94.4-100%, which was higher than the primary group except for serotypes 6B and 14 (P<.05). The percentage of subjects with pneumococcal antibodies ${\geq}5.0{\mu}g/mL$ in the booster group was 50.0-94.4% which was higher than the primary group for all serotypes (P<0.05). Conclusion : The immunogenicity of a booster dose of the pneumococcal conjugate vaccine in Korean children was high and the immunogenicity of a primary series was also relatively high. To determine the feasibility of the introduction of the pneumococcal conjugate vaccine and the appropriate schedule for Korean children, further prospective investigation of the immunogenicity of the booster immunization is needed.

• Clinical and Experimental Pediatrics
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• v.59 no.12
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• pp.461-465
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• 2016

This report includes the recommended immunization schedule table for children and adolescents based on the 8th (2015) and revised 7th (2012) Immunization Guidelines released by the Committee on Infectious Diseases of the Korean Pediatric Society (KPS). Notable revised recommendations include: reorganization of the immunization table with a list of vaccines on the vertical axis and the corresponding age on the horizontal axis; reflecting the inclusion of Haemophilus influenzae type b vaccine, pneumococcal conjugate vaccine, and hepatitis A vaccine into the National Immunization Program since 2012; addition of general recommendations for 2 new Japanese encephalitis (JE) vaccines and their interchangeability with existing JE vaccines; addition of general recommendations for quadrivalent meningococcal conjugate vaccines and scope of the recommended targets for vaccination; and emphasizing catch-up immunization of Tdap vaccine. Detailed recommendations for each vaccine may be obtained from the full KPS 8th Immunization Guidelines.

• Journal of Yeungnam Medical Science
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• v.29 no.1
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• pp.1-8
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• 2012

Streptococcus pneumonia is a very important pathogen for children and elderly people. Two types of pneumococcal vaccines are available in the market: pneumococcal polysaccharide vaccine (PPSV) and pneumococcal conjugate vaccine (PCV). PPSVs have been used for more than 30 years, and PCVs for about 10 years. There have been many reports concerning the evaluation of the vaccines' efficacies in preventing pneumococcal diseases such as meningitis, pneumonia, and otitis media and bacteremia, but the clinical trials had been performed with different conditions, such as diverse vaccine valencies, age groups, races, target outcomes, immunological cut-off values, and follow-up periods. PPSV is recommended for elderly people and chronic disease patients such as asthma, diabetes mellitus, chronic renal failure, and hyposplenic patients. According to the data from several systemic reviews and population-based surveillances, PPSV is effective for pneumococcal pneumonia and vaccine-type bacteremia among healthy adults. Until now, however, there is insufficient evidence of the effectiveness of PPSV among high-risk adults. PCV is very effective in preventing vaccine-type invasive pneumococcal disease (IPD) among children, but its efficacy for pneumonia is very low among children. The incidence of vaccine-related or non-vaccine-type IPDs is increasing after the introduction of 7-valent PCV (PCV7) as a routine immunization for children. Recently, 10- and 13-valent PCVs have been used for children, instead of PCV7. Therefore, continuous surveillance for serotype change among pneumococcal diseases is necessary to evaluate the vaccines' efficacy.

• Pediatric Infection and Vaccine
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• v.20 no.2
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• pp.53-62
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• 2013

Purpose: The cross-protection of 7-valent pneumococcal conjugate vaccine (PCV7) against vaccine-related serotypes has been controversial. We investigated the serological properties of cross-protective antibodies against vaccine-related serotypes 6A, 6C, and 19A induced in young children aged 12-23 months after booster immunization of PCV7. Methods: IgG and IgM antibody concentrations and opsonic index (OI) against vaccine serotypes 6B and 19F and vaccine-related serotypes 6A, 6C, and 19A were measured by ELISA and opsonophagocytic killing assay (OPA) in 4 selected immunesera. The serological properties and antigenic specificity of protective antibodies were determined by IgM depletion of immunesera, OPA, and competitive OPA against serogroup 6 and 19 pneumococci. Results: Compared to pre-IgM depleted immunesera, OI of IgM-depleted immunesera against 6B and 19F decreased and OI against 6A, 6C, and 19A decreased, too. In competition OPA, free 6B and 19F polysaccharide completely inhibited the immune protection against vaccine-related serotypes 6A, 6C, and 19A as well as vaccine types 6B and 19F. Conclusions: The booster immunization of PCV7 certainly induced cross-protective antibodies against vaccine-related serotypes 6A, 6C, and 19A with both IgG and IgM isotypes. Furthermore, IgM antibodies are more highly contributed to opsonophagocytic activity against vaccine-related serotypes as well as most of vaccine types than do IgG antibodies. Further studies are needed for the more immunized sera in the children as well as adults.

• Pediatric Infection and Vaccine
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• v.16 no.1
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• pp.13-23
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• 2009

Acute otitis media (AOM) and pneumonia are among the most common infectious diseases of children. Both are mucosal infections and share many common features such as etiological agents, pathogenesis and immunity. Influenza plays an important role in the pathogenesis of AOM and pneumonia. A vaccine against influenza may have substantial impact on these diseases during the influenza season. In clinical trials, influenza vaccine has reduced the incidence of AOM and pneumonia complicating influenza in children. However, the efficacy of vaccines has been controversial in children less than 2 years of age. Similarly, vaccines against Streptococcus pneumoniae and Haemophilus influenzae type b (Hib), both common causes of AOM and pneumonia, have the potential to reduce the impact of disease. Clinical trials showed that the currently licensed 7-valent pneumococcal conjugate vaccine (PCV), administered during infancy, had an efficacy of 6-7% for the prevention of AOM, however, visits to the clinic for AOM were reduced by up to 20-30% after routine use in the U.S. Both Hib and PCVs have a proven effectiveness of >20% for prevention of radiologically confirmed pneumonia in children. The recently introduced pnuemococcal vaccine conjugated with protein D is expected to reduce AOM and pneumonia caused by non-typable H. influenzae, in addition to its effects on pneumococcal diseases. Considering their high incidence in children, recent achievements in the prevention of AOM and pneumonia with vaccines may have a significant economic and social impact.

• Clinical and Experimental Pediatrics
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• v.63 no.7
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• pp.265-271
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• 2020

Background: Pneumococcal diseases among children aged <5 years worldwide are associated with high annual mortality rates. Purpose: This study aimed to evaluate the immunogenicity and safety of GBP411, a 12-valent pneumococcal conjugant vaccine, with a dosing schedule of 2 primary doses plus 1 booster dose (2p+1) in healthy infants. Methods: This randomized active-controlled (Prevnar 13) double-blind phase 2 trial enrolled healthy subjects aged 6-10 weeks. Three serum concentrations of pneumococcal serotype-specific immunoglobulin G (IgG) were evaluated using the pneumococcal serotype-specific pneumonia polysaccharide enzyme-linked immunosorbent assay at 1 month after the primary doses and before and 1 month after the booster dose. The pneumococcal serotype-specific IgG titer was evaluated using a multiplex opsonophagocytic assay in a subset of 15 subjects per group. Results: After administration of the primary doses, the proportion of subjects who achieved pneumococcal serotype-specific IgG concentrations of >0.35 ㎍/mL was lower for some serotypes in the GBP411 group than in the comparator group (6B: 20.83% vs. 39.22%, P=0.047 and 19A: 58.33% vs. 90.20%, P<0.001). However, after administration of the booster dose, >97% of the subjects in each group achieved IgG concentrations of ≥0.35 ㎍/mL for all 12 serotypes. Increased immunogenicity was observed for some serotypes that showed significant intergroup differences after administration of the primary doses but not after the booster dose. We also found no significant intergroup difference in the overall incidence of solicited local adverse events. Furthermore, the overall incidence of solicited systemic adverse events was significantly lower in the GBP411 group than in the comparator vaccine group (79.59% vs. 98.04%; P=0.003). Conclusion: The GBP411 vaccine with a dosing schedule of 2p+1 may be immunogenic and safe for healthy infants.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.846-853
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• 2003

Purpose : Pneumoccocus is one of the most important causes of invasive infection through the childhood period and the prevelance of antibiotics resistance of pneumococcus is increasing worldwide. A 7-valent conjugate vaccine has been developed. It is important to know the prevalence of each serotype of pneumococci in the countries where the vaccine is used to estimate the coverage rate by the vaccine. Methods : One hundred and twenty seven strains of clinical isolates and 72 strains from healthy carriers recovered from Korean children during the period from 1997 to 2002 were subjected to determination of serotype by Quellung reaction and penicillin susceptibility with oxacillin disc diffusion test. Results : Forty-three per cent of clinical isolates were obtained from children under two years of age. Thirty strains(24%) were isolated from normally sterile body fluids. The frequent serotypes were 19F, 19A, 23F, 6A, 6B and 9V. Fifty-six per cent of the clinical isolates were represented in the current 7-valent protein conjugate pneumococccal vaccine, and 84% when the cross-reactive serotypes were included. Frequent serotypes of strains isolated from one to five year-old healthy children were 19F, 14, 11A, 23F, 18C, and 19A. Seventy-one per cent of the carrier strains were included in the 7-valent vaccine. Ninety-three per cent of the clinical isolates and 86% of carrier strains were not susceptible to penicilline. Conclusion : Fifty-six to 84% of pneumococci recovered from Korean children are covered by the current 7-valent protein conjugate pneumococcal vaccine and the prevalence of penicillin resistance was very high.