• Clinical and Experimental Pediatrics
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• v.57 no.2
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• pp.55-66
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• 2014

The 7-valent pneumococcal protein conjugate vaccine (PCV7) has been shown to be highly efficacious against invasive pneumococcal diseases and effective against pneumonia and in reducing otitis media. The introduction of PCV7 has resulted in major changes in the epidemiology of pneumococcal diseases. However, pneumococcal vaccines induce serotype-specific immunity, and a relative increase in non-vaccine serotypes has been reported following the widespread use of PCV7, leading to a need for extended serotype coverage for protection. PCV10 and PCV13 have been licensed on the basis of noninferiority of immunogenicity compared to a licensed conjugate vaccine. In this article, we aimed to review important data regarding the efficacy and effectiveness of the extended-coverage PCVs published or reported thus far and to discuss future implications for pneumococcal vaccines in Korea. After the introduction of PCV10 and PCV13, within a short period of time, evidence of protection conferred by these vaccines against invasive and mucosal infections caused by most of the serotypes included in the vaccines is accumulating. The choice of vaccine should be based on the changes in the dynamics of pneumococcal serotype distribution and diseases in the region where the vaccines are to be used. Continuous surveillance is essential for the appropriate use of pneumococcal vaccines and evaluation of the impact of PCVs on pneumococcal diseases.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.242-250
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• 2006

Haemophilus influenzae type b(Hib) conjugate vaccines prevent Hib disease in individuals and reduce the carriage and transmission of the organism in the community. The incidence of Hib disease has been decreased dramatically in a diverse range of countries through the use of a variety of conjugate vaccines and vaccine schedules. In some countries, the vaccine has caused a near-disappearance of invasive Hib disease through a combination of direct protection and herd immunity. The effectiveness of the vaccine was not modified by the type of conjugate vaccine, the number of doses given(two, three or four), age at first vaccination(two months, 42 to 90 days, three months) and whether the vaccine was tested in an industrialized or developing country. Over 15 years of international experience with vaccines has also demonstrated that they are safe. In 2004, Hib vaccines were adapted in routine immunization in 92 countries in the world. Decisions regarding the use of the Hib vaccine in routine immunization schedules depend not only on the effectiveness and efficacy of the vaccine but also on factors such as burden of disease, vaccine cost, and competing priorities. In Korea, Hib disease burden seemed to be lower than other developed countries(~10/100,000). Moreover Hib vaccines showed excellent immunogenicity in Korean children in many studies. Therefore, a potential approach to economize the cost of Hib vaccines could be to explore the possibilities of using reduced vaccine doses for immunization as some other countries.

• Journal of Microbiology and Biotechnology
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• v.28 no.12
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• pp.2113-2120
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• 2018

Cross-reactive material 197 ($CRM_{197}$) is a non-toxic mutant of diphtheria toxin containing a single amino acid substitution of glycine 52 with glutamic acid. $CRM_{197}$ has been used as a carrier protein for poorly immunogenic polysaccharide antigens to improve immune responses. In this study, to develop a sandwich ELISA that can detect $CRM_{197}$ and $CRM_{197}$ conjugate vaccines, we generated a human anti-$CRM_{197}$ monoclonal antibody (mAb) 3F9 using a phage-displayed human synthetic Fab library and produced mouse anti-$CRM_{197}$ polyclonal antibody. The affinity ($K_D$) of 3F9 for $CRM_{197}$ was 3.55 nM, based on Bio-Layer interferometry, and it bound specifically to the B fragment of $CRM_{197}$. The sandwich ELISA was carried out using 3F9 as a capture antibody and the mouse polyclonal antibody as a detection antibody. The detection limit of the sandwich ELISA was <1 ng/ml $CRM_{197}$. In addition, the 3F9 antibody bound to the $CRM_{197}$-polysaccharide conjugates tested in a dose-dependent manner. This ELISA system will be useful for the quantification and characterization of $CRM_{197}$ and $CRM_{197}$ conjugate vaccines. To our knowledge, this study is the first to generate a human monoclonal antibody against $CRM_{197}$ and to develop a sandwich ELISA for $CRM_{197}$ conjugate vaccines.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.490-494
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• 2004

An efficacy test of PRP (polyribosylribitol phosphate)-TT (Tetanus toxoid) conjugate vaccines was carried out using BALB/c mice as an animal model by inoculating Haemophilus in­fluenzae type b (Hib) with a virulence enhancement factor (VEF). Three administrations of the conjugate vaccines at 2-week intervals elicited a significantly high level of PRP antibodies (P>0.0001). The protective activity of the PRP immunization was challenged with either Hib with iron dextran (Hib/) or with a combination of mucin and hemoglobin (Hibmh) as a VEF. The me­dium lethal dose $(LD_{50})$ for Hibmh and Hibiwas measured as 10 CFU (Colony Forming Unit) and $2.5{\times}10^{8}$ CFU respectively. Each immunized animal was challenged with five or ten times the $LD_{50}$ level of bacteria with a VEF. A significant difference in mortality between the immunized and control mice (P> 0.01) was observed with the Hibmh challenge inoculation but not with the Hibi challenge inoculation. These results show that a combination of mucin and hemoglobin was able to enhance the virulence of Hib in BALB/c mice to cause a lethal infection, thus suggesting that BALB/c mice introduced to this method can be an effective model animal for testing the protective efficacy of H. influenzae conjugate vaccines.

• Clinical and Experimental Pediatrics
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• v.54 no.4
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• pp.146-151
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• 2011

Streptococcus pneumoniae remains a leading cause of invasive infections including bacteremia and meningitis, as well as mucosal infections such as otitis media and pneumonia among children and adults. The 7-valent pneumococcal conjugate vaccine (PCV7) was licensed for use among infants and young children in many countries including Korea. The routine use of PCV7 has resulted in a decreased incidence of invasive pneumococcal disease (IPD) by the vaccine serotypes among the vaccinees and substantial declines in IPD among unvaccinated populations such as older children and adults as well. In addition, there are increasing evidences to suggest that routine immunization with PCV7 is changing the epidemiology of pneumococcal diseases such as serotype distribution of IPD, nasopharyngeal colonization, and antibiotic resistance patterns. In contrast, there is an increase in the number of IPDs caused by nonvaccine serotypes, though it is much smaller than overall declines of vaccine serotype diseases. Several vaccines containing additional serotypes have been developed and tested clinically in order to expand the range of serotypes of Streptococcus pneumoniae. Recently two new pneumococcal protein conjugate vaccines, 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13), have been approved for use in several countries including Korea. This report summarizes the recommendations approved by the Committee on Infectious Diseases, the Korean Pediatric Society.

• Clinical and Experimental Pediatrics
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• v.63 no.7
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• pp.259-260
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• 2020

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.215-222
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• 2006

The Lowry method was used in this study to measure protein in Haemophilus influenzae type b (Hib) conjugate vaccines (polyribosylibitol phosphate-tetanus toxoid; PRP-TT) using deoxycholic acid (DOC) to induce protein precipitation. Trichloroacetic acid (TCA) did not induce precipitation adequately from the Hib conjugate bulk and the freeze-dried Hib conjugate product. Its yield was approximately 50%. The matrix structure of Hib conjugate inhibits precipitation by TCA. Although the Lowry method can be carried out without precipitation in Hib conjugate bulk when no residual impurities (adipic acid dihydrazide [ADH], 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide-HCI [EDAC], phenol and cyanogens bromide [CNBr], etc.) are present, it cannot be used for Hib conjugate products that contain sucrose 8.5%, because 8.5% concentration of sucrose enhanced the protein concentration. DOC- and HCl-induced precipitation is an alternative method for evaluating the protein content of the Hib conjugate bulk and the Hib conjugate product. The precipitation was optimal with a final concentrate of 0.1% for DOC at $4^{\circ}C$ and pH 2. This Lowry method, using DOC/HCI precipitation to induce protein precipitation, was confirmed a consistent, reproducible, and valid test for proteins in Hib conjugate bulk and its freeze-dried product.

• 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.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.147-148
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• 2002

Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis are encapsulated bacteria which encounter the respiratory mucosa and cause nasopharyngeal carriage that may lead to mild mucosal infections or severe invasive disease. (omitted)

• Infection and chemotherapy
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• v.50 no.4
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• pp.287-300
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• 2018

Pneumonia is the leading cause of morbidity and mortality, particularly in old adults. The incidence and etiologic distribution of community-acquired pneumonia is variable both geographically and temporally, and epidemiology might evolve with the change of population characteristics and vaccine uptake rates. With the increasing prevalence of chronic medical conditions, a wide spectrum of healthcare-associated pneumonia could also affect the epidemiology of community-acquired pneumonia. Here, we provide an overview of the epidemiological changes associated with community-acquired pneumonia over the decades since pneumococcal conjugate vaccine introduction.