Early Changes in the Serotype Distribution of Invasive Pneumococcal Isolates from Children after the Introduction of Extended-valent Pneumococcal Conjugate Vaccines in Korea, 2011-2013.

This study was performed to measure early changes in the serotype distribution of pneumococci isolated from children with invasive disease during the 3-year period following the introduction of 10- and 13-valent pneumococcal conjugate vaccines (PCVs) in Korea. From January 2011 to December 2013 at 25 hospitals located throughout Korea, pneumococci were isolated among children who had invasive pneumococcal disease (IPD). Serotypes were determined using the Quellung reaction, and the change in serotype distribution was analyzed. Seventy-five cases of IPD were included. Eighty percent of patients were aged 3-59 months, and 32% had a comorbidity that increased the risk of pneumococcal infection. The most common serotypes were 19A (32.0%), 10A (8.0%), and 15C (6.7%). The PCV7 serotypes (4, 6B, 9V, 14, 18C, 19F, 23F, and 6A) accounted for 14.7% of the total isolates and the PCV13 minus PCV7 types (1, 3, 5, 7F and 19A) accounted for 32.0% of the total isolates. Serotype 19A was the only serotype in the PCV13 minus PCV7 group. The proportion of serotype 19A showed decreasing tendency from 37.5% in 2011 to 22.2% in 2013 (P = 0.309), while the proportion of non-PCV13 types showed increasing tendency from 45.8% in 2011 to 72.2% in 2013 (P = 0.108). Shortly after the introduction of extended-valent PCVs in Korea, serotype 19A continued to be the most common serotype causing IPD in children. Subsequently, the proportion of 19A decreased, and non-vaccine serotypes emerged as an important cause of IPD. The impact of extended-valent vaccines must be continuously monitored.

Safety and immunogenicity of a freeze-dried, Vero cell culture-derived, inactivated Japanese encephalitis vaccine (KD-287, ENCEVAC®) versus a mouse brain-derived inactivated Japanese encephalitis vaccine in children: a phase III, multicenter, double-blinded, randomized trial.

BACKGROUND: Although mouse brain-derived, inactivated Japanese encephalitis vaccines (JE-MBs) have been successfully used for a long time, potential rare neurological complications have prompted the development of a Vero cell culture-derived inactivated vaccine (JE-VC). In a phase III clinical study, we aimed to compare the safety and immunogenicity of a JE-VC, KD-287 with a JE-MB, JEV-GCC, in children. METHODS: In this multicenter, double-blinded, randomized controlled trial, the study population consisted of 205 healthy Korean children aged 12-23 months. Each subject was subcutaneously vaccinated with either KD-287 or JEV-GCC twice at an interval of 2 weeks and then vaccinated once 12 months after the second vaccination. Neutralizing antibodies were measured by the plaque reduction neutralization test using the homologous and heterologous, as a post hoc analysis, challenge virus strains. RESULTS: The three-dose regimen of KD-287 showed a comparable safety profile with JEV-GCC except higher incidence of fever after the first dose (30.4% and 14.7%, respectively). Most of the fever was mild degree (61.3% and 66.7%, respectively). KD-287 fulfilled the non-inferiority criteria for seroconversion rate (SCR) and geometric mean titer (GMT) of the neutralizing antibody, which were the primary endpoints, at 4 weeks after the third vaccination (95% CI: -1.00, 3.10 for the SCR difference and 10.8, 17.6 for the GMT ratio). The SCRs of KD-287 were all 100% and the GMTs were higher in the KD-287 group than in the JEV-GCC group after the second vaccination and before and after the third vaccination (GMT ratio: 5.59, 20.13, and 13.79, respectively, p < 0.001 in all). GMTs were higher in the KD-287 group in the heterologous analysis also (GMT ratio: 4.05, 5.15, and 4.19, respectively, p < 0.001 in all). CONCLUSIONS: This study suggests that the KD-287, a JE-VC is as safe as and may be more effective than the licensed MB-derived vaccine. KD-287 could thus be useful as a second-generation vaccine and substitute for the current JE-MB vaccine in Korean children. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01150942.

Recent change in congenital syphilis in Korea: Retrospective 10 year study.

BACKGROUND: This study was conducted to evaluate recent clinical and anthropologic features of neonates with reactive serology for syphilis and their mothers from three institutions in Korea over an 11-year-period. METHOD: The medical records of 20 neonates with reactive serology for syphilis and their mothers at three centers (Kyung Hee University Hospital, Kyung Hee University Hospital at Gangdong, and Korea Electric Power Corporation Hospital) seen between January 2000 and December 2010 were reviewed retrospectively. RESULTS: Among 20 mothers, 16 (80%) were native Korean and four (20%) were foreign-born immigrants. Two mothers (10%) were unmarried. The annual distribution of cases was three (15%) in 2000, one each (5%) in 2005 and 2006, respectively, two each (10%) in 2007 and 2008, respectively, six (30%) in 2009, and five (25%) in 2010. Just over half (55%) occurred across 2009 and 2010. All neonates, by definition, were diagnosed with presumptive congenital syphilis (CS). Among the neonates, four had positive cerebrospinal fluid venereal disease research laboratory test, and three exhibited symptoms and signs. CONCLUSIONS: In three centers in Seoul, Korea, the observed number of CS cases was higher in 2009 and 2010 than in previous years. This finding is consistent with a trend toward increasing prevalence of international marriage and suggests that more meticulous screening of CS is needed.

N-terminal pro-brain natriuretic peptide (NT proBNP) as a predictive indicator of initial intravenous immunoglobulin treatment failure in children with Kawasaki disease: a retrospective study.

Intravenous immunoglobulin (IVIG) administered in the acute stage of Kawasaki disease (KD) is the standard therapy. Few reports describe nonresponders to initial treatment with IVIG in KD, which remains the most consistent risk factor for coronary artery lesions (CALs). This study aimed to investigate whether the serum level of N-terminal pro-brain natriuretic peptide (NT-proBNP) can be a predictive indicator for identifying patients with KD at higher risk of IVIG treatment failure. In this study, 135 patients with a diagnosis of KD admitted for IVIG treatment were retrospectively enrolled for analysis. Of these 135 patients, 22 were nonresponders who received additional rescue therapy because they had an elevated body temperature 36 h after completion of initial IVIG treatment. The NT-proBNP concentration was significantly higher in the nonresponder group (2,465.36 ± 3,293.24 pg/mL) than in the responder group (942.38 ± 1,293.48 pg/mL) (p < 0.05). The optimal sensitivity and specificity cutoff point for predicted nonresponders was 1,093.00 pg/mL or higher. The sensitivity and specificity for prediction of IVIG response were respectively 70.0 and 76.5 %. The findings show that NT-proBNP is a helpful marker in determining patients at risk for not responding to initial IVIG treatment. The authors suggest that patients with an NT-proBNP level of 1,093.00 pg/dL or higher are likely to fail initial IVIG and may require further rescue therapy.

Safety and immunogenicity of a new trivalent inactivated split-virus influenza vaccine in healthy Korean children: a randomized, double-blinded, active-controlled, phase III study.

We report results of a randomized, double-blinded, active-controlled, phase III study conducted to evaluate the immunogenicity and safety of a new trivalent inactivated split-virus influenza vaccine (GC501) manufactured by the Green Cross Corporation in Korea. A total of 283 healthy children aged 6 months to < 18 yr were randomized to receive either GC501 or control. Of the GC501 recipients, seroconversion occurred in 48.5% for A/H1N1, 67.7% for A/H3N2 and 52% for influenza B. The proportion of subjects who had post-vaccination hemagglutination-inhibition titers of 1:40 or greater was 90.7% for A/H1N1, 86.8% for A/H3N2 and 82.4% for influenza B in the GC501 recipients. No serious adverse events related to vaccination, or withdrawals because of adverse events were reported. The majority of solicited adverse events were mild in intensity. GC501 vaccine has good tolerability and favorable immunogenicity in children aged 6 months to < 18 yr. The addition of one more brand of influenza vaccine may allow for better global accessibility of vaccine for epidemics or future pandemics.

Etiology of invasive bacterial infections in immunocompetent children in Korea (1996-2005): a retrospective multicenter study.

The purpose of this study was to identify the major etiological agents responsible for invasive bacterial infections in immunocompetent Korean children. We retrospectively surveyed invasive bacterial infections in immunocompetent children caused by eight major pediatric bacteria, namely Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species that were diagnosed at 18 university hospitals from 1996 to 2005. A total of 768 cases were identified. S. agalactiae (48.1%) and S. aureus (37.2%) were the most common pathogens in infants younger than 3 months. S. agalactiae was a common cause of meningitis (73.0%), bacteremia without localization (34.0%), and arthritis (50%) in this age group. S. pneumoniae (45.3%) and H. influenzae (20.4%) were common in children aged 3 months to 5 yr. S. pneumoniae was a common cause of meningitis (41.6%), bacteremia without localization (40.0%), and bacteremic pneumonia (74.1%) in this age group. S. aureus (50.6%), Salmonella species (16.9%), and S. pneumoniae (16.3%) were common in older children. A significant decline in H. influenzae infections over the last 10 yr was noted. S. agalactiae, S. pneumoniae, and S. aureus are important pathogens responsible for invasive bacterial infections in Korean children.

Effect of paranasal sinusitis on the development of otitis media with effusion: influence of eustachian tube function and adenoid immunity.

OBJECTIVES: Concordance between sinusitis and otitis media with effusion (OME) has been reported in 5-60% of patients. Since nasal diseases induce edema and lymphoid tissue hyperplasia in the nasopharyngeal mucosa, especially the adenoids, chronic infection of the adenoids has been reported to induce otitis media. In addition, deterioration in the mucosal barrier of the adenoids makes the latter vulnerable to bacterial infections, resulting in OME or sinusitis. We therefore evaluated adenoid local immunity and Eustachian tube function by sinusitis and the concordance between sinusitis and OME. MATERIALS AND METHODS: We examined PNS series and tympanometry of 520 patients who had undergone adenotonsillectomies. In addition, local adenoidal immunity was evaluated in 10 children with OME and sinusitis, 11 with only sinusitis, 10 with only OME and 12 with no history of OME or sinusitis. Adenoid size, squamous metaplasia, IgA, BCL-6, and mucosal barrier were also determined. RESULTS: Of 520 patients, 80 (15.4%) had both OME and sinusitis. The incidence of Eustachian tube dysfunction differed significantly between patients with and without sinusitis (p=0.03). The incidence of squamous metaplasia differed significantly between patients with sinusitis plus OME and patients with sinusitis alone (p=0.01), and between patients with OME alone and those without both conditions (p=0.005). Patients with both sinusitis and OME differed significantly in IgA secretion (p=0.01) and Bcl-6 expression (p=0.02) from those with sinusitis alone, as did patients with OME alone and those without both conditions (p=0.02 and p=0.03, respectively). CONCLUSIONS: Sinusitis plus OME were present in 15.4% of patients. Eustachian tube dysfunction was present in 37.9% of sinusitis patients and in 28.4% of those without sinusitis. IgA, BCL-6 and squamous metaplasia were important in local adenoidal immunity.

An infant presenting with Kawasaki disease following immunization for influenza: A case report.

Kawasaki disease (KD) is a childhood vascular disorder of unknown etiology. Concerns have recently been raised regarding vaccinations as a potential risk factor for KD. In addition, various forms of vasculitis have been reported as adverse events following administration after various vaccines. Patients exhibiting post vaccination KD have previously been described; however, thus far, to the best of our knowledge, only one patient exhibiting post influenza vaccination KD has been reported in Japan. The present study describes a case of KD 24 h after immunization with influenza in an infant (age, 18 months) following 6 days of high fever, a body rash that had persisted for 2 days and nonsuppurative bilateral conjunctivitis. To the best of the authors' knowledge, this is the first reported case in Korea and the present study reviews various recent studies regarding vasculitis following vaccination and the causal association between them.

Immunogenicity and safety of the quadrivalent meningococcal vaccine MenACWY-TT co-administered with a combined diphtheria-tetanus-acellular pertussis vaccine versus their separate administration in adolescents and young adults: A phase III, randomized study.

BACKGROUND: This study evaluated the immunogenicity and safety of quadrivalent meningococcal conjugate vaccine using tetanus (T) toxoid as carrier protein (MenACWY-TT) co-administered with combined diphtheria-tetanus-acellular pertussis vaccine (Tdap) versus their separate administration in adolescents and young adults. METHODS: In this phase III, randomized, partially-blind study (NCT01767376), healthy 11-25-year-olds (N = 660) were randomized (1:1:1) to receive MenACWY-TT and Tdap at Month 0 (Co-ad group), MenACWY-TT at Month 0 and Tdap at Month 1 (ACWY_Tdap group) or Tdap at Month 0 and MenACWY-TT at Month 1 (Tdap_ACWY group). Immune responses to MenACWY-TT were measured by serum bactericidal assay using rabbit complement (rSBA). Anti-diphtheria (D), anti-tetanus (T), anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA) and anti-pertactin (PRN) antibody concentrations were assessed using enzyme-linked immunosorbent assays. Non-inferiority of immunogenicity was assessed using pre-defined clinical criteria. Safety was also evaluated. RESULTS: Non-inferiority of immunogenicity of MenACWY-TT and Tdap when co-administered versus their separate administration was demonstrated in terms of rSBA geometric mean titers (GMTs) for 4 meningococcal serogroups and of the percentage of participants with antibody concentrations >1 IU/ml for D and T. Among the pertussis antigens, non-inferiority criteria for geometric mean concentrations (GMCs) were reached for PT, but not met for FHA and PRN. Across all groups, ≥93.2% of participants had vaccine responses to each meningococcal serogroup, ≥99.1% were seroprotected against T and D, and ≥85.5% had booster responses to each pertussis antigen. Robust increases in antibody GMTs/GMCs were observed for all antigens between pre-and post-vaccination. Both vaccines had clinically acceptable safety profiles. CONCLUSION: Immune responses to MenACWY-TT and to the T and D antigens from Tdap were not impacted by their co-administration. The lower antibody concentrations observed against the pertussis components may be of limited clinical relevance since robust anti-pertussis booster responses were observed. This study supports concurrent administration of the 2 vaccines in adolescents.

Long-term immunogenicity of an initial booster dose of an inactivated, Vero cell culture-derived Japanese encephalitis vaccine (JE-VC) and the safety and immunogenicity of a second JE-VC booster dose in children previously vaccinated with an inactivated, mouse brain-derived Japanese encephalitis vaccine.

BACKGROUND: This study was performed with the aim of determining the long-term immunogenicity of an inactivated, Vero cell culture-derived Japanese encephalitis (JE) vaccine (JE-VC) and an inactivated, mouse brain-derived JE vaccine (JE-MB) after the 1st booster dose at 2 years of age, as well as the safety and immunogenicity of the 2nd booster dose of JE-VC at 6 years of age, in children primed and given a 1st booster dose of either JE-VC or JE-MB. METHOD: In this multicenter, open-label clinical trial, the study population consisted of healthy Korean children (aged 6 years) who participated in the previous JE vaccine trial. All subjects were subcutaneously vaccinated once for the booster immunization with Boryung Cell Culture Japanese Encephalitis Vaccine® (JE-VC). RESULT: Approximately 4 years after the 1st booster dose of JE-VC, the seroprotection rate (SPR) and geometric mean titer (GMT) of the neutralizing antibody were 100% and 1113.8, respectively. In children primed and given a 1st booster dose of JE-MB, the SPR and GMT were 88.5% and 56.3, respectively. After the 2nd booster dose of JE-VC, all participants primed and given a 1st booster dose of either JE-MB or JE-VC were seroprotective against JE virus. The GMT of the neutralizing antibody was higher in children primed and given a 1st booster dose of JE-VC (8144.1) than in those primed and given a 1st booster dose of JE-MB (942.5) after the vaccination (p < 0.001). In addition, the 2nd booster dose of JE-VC showed a good safety profile with no serious vaccine-related adverse events. CONCLUSION: The 1st booster dose of JE-VC and JE-MB showed long-term immunogenicity of at least 4 years, and the 2nd booster dose of JE-VC showed a good safety and immunogenicity profile in children primed and given a 1st booster dose of either JE-VC or JE-MB. ClinicalTtrials.gov Identifier: NCT02532569.

Kawasaki disease in Korea, 2003-2005.

PURPOSE: The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for the 3-year-period, 2003-2005. METHODS: The questionnaire for an epidemiologic survey on Kawasaki disease was distributed to all 102 Korean hospitals that conduct pediatric residency programs, and obtained data were analyzed upon receipt. RESULTS: The 9662 patients of Kawasaki disease from 85 hospitals that responded (response rate, 83.3%) consisted of 5877 males and 3785 females (male:female ratio, 1.55:1). The incidence rate per 100,000 children <5-year-old was 104.2 in 2003, 106.4 in 2004, and 104.6 in 2005 (average rate, 105.0). Their mean age of onset was 33.3 months, and the proportions of sibling cases and recurrent cases were 0.29% and 2.0%, respectively. Coronary arterial abnormalities were detected at follow-up by echocardiogram in 18.8% of all such cases including dilatations of 18.0% and aneurysms of 2.5%. CONCLUSION: The average annual rate of incidence, 105.0/100,000 in children <5-year-old is the second highest reported rate in the world.

Safety and immunogenicity of a single dose of a quadrivalent meningococcal conjugate vaccine (MenACYW-D): a multicenter, blind-observer, randomized, phase III clinical trial in the Republic of Korea.

OBJECTIVES: To assess the safety and immunogenicity of a meningococcal polysaccharide diphtheria toxoid conjugate vaccine (MenACYW-D) in a Korean population. METHODS: This was a phase III, blind-observer, controlled study in which participants aged 11-55 years were randomized (2:1 ratio) to a single dose of MenACYW-D or tetanus/diphtheria/acellular pertussis (Tdap) vaccine. Outcomes included rates of seroconversion against all serogroups (≥4-fold increase in antibody titer from pre-vaccination), geometric mean titers (GMTs) at days 0 and 28 based on a serum bactericidal assay using baby rabbit complement, rates of seroprotection (titer ≥1:128) at day 28, and safety. RESULTS: A total of 300 participants were enrolled in the study (200 MenACYW-D and 100 Tdap). Seroconversion rates for serogroups A, C, Y, and W-135 were 77.8%, 88.3%, 74.6%, and 92.4%, respectively, for the MenACYW-D group and 9.3%, 8.1%, 12.2%, and 8.2%, respectively, for the Tdap group. The proportions of participants with pre-vaccination titers ≥1:128 were 57.3%, 12.6%, 51.5%, and 22.2% for serogroups A, C, Y, and W-135, respectively; post-vaccination rates were 98.5%, 89.4%, 96.0%, and 95.0% for the MenACYW-D group. A lower proportion of participants reported solicited reactions with MenACYW-D (46.2%) compared with Tdap (76.8%). CONCLUSION: A single dose of MenACYW-D was well tolerated and elicited a robust immune response in Korean adolescents and adults.

Immunogenicity and Safety of a Booster Dose of a Live Attenuated Japanese Encephalitis Chimeric Vaccine Given 1 Year After Primary Immunization in Healthy Children in the Republic of Korea.

BACKGROUND: This study evaluated the effect of a booster vaccination of a new, live attenuated, Japanese encephalitis chimeric vaccine (JE-CV). Previously this vaccine has been used as a booster 12 months after priming with an inactivated vaccine and at >24 months after priming with the same JE-CV. This study evaluates the immunogenicity and safety of the JE-CV given at 12-24 months after JE-CV priming. METHODS: Phase III, open-label study in the Republic of Korea in which 119 children previously vaccinated with JE-CV at 12-24 months of age received a JE-CV booster at 12-24 months after primary vaccination. JE neutralizing antibody titers were measured using >50% plaque reduction neutralization test prebooster and 1 month postbooster vaccination. Seroprotection (SP) was defined as ≥10 (1/dil). Safety was assessed for 28 days postvaccination by parental reports. Serious adverse events were monitored for 6 months postvaccination. RESULTS: Antibody persistence was high prebooster (SP rate 93.5%). There was a strong anamnestic response postbooster vaccination, with an SP rate of 100% and a >50-fold increase in geometric mean titer from the prebooster level. Both antibody persistence and the booster response were independent of whether the booster was given at 12-17 or 18-24 months. The safety profile was good and comparable with the primary vaccination; there were no vaccine-related serious adverse events and no deaths. CONCLUSIONS: This study confirms the suitability of a JE-CV booster vaccination at 12-24 months after a primary dose of the same vaccine given at 12-24 months of age in children in the Republic of Korea.

Immunogenicity and safety assessment of a trivalent, inactivated split influenza vaccine in Korean children: Double-blind, randomized, active-controlled multicenter phase III clinical trial.

A multicenter, double-blind, randomized, active-control phase III clinical trial was performed to assess the immunogenicity and safety of a trivalent, inactivated split influenza vaccine. Korean children between the ages of 6 months and 18 y were enrolled and randomized into a study (study vaccine) or a control vaccine group (commercially available trivalent, inactivated split influenza vaccine) in a 5:1 ratio. Antibody responses were determined using hemagglutination inhibition assay, and post-vaccination immunogenicity was assessed based on seroconversion and seroprotection rates. For safety assessment, solicited local and systemic adverse events up to 28 d after vaccination and unsolicited adverse events up to 6 months after vaccination were evaluated. Immunogenicity was assessed in 337 and 68 children of the study and control groups. In the study vaccine group, seroconversion rates against influenza A/H1N1, A/H3N2, and B strains were 62.0% (95% CI: 56.8-67.2), 53.4% (95% CI: 48.1-58.7), and 54.9% (95% CI: 48.1-60.2), respectively. The corresponding seroprotection rates were 95.0% (95% CI: 92.6-97.3), 93.8% (95% CI: 91.2-96.4), and 95.3% (95% CI: 93.0-97.5). The lower 95% CI limits of the seroconversion and seroprotection rates were over 40% and 70%, respectively, against all strains. Seroconversion and seroprotection rates were not significantly different between the study and control vaccine groups. Furthermore, the frequencies of adverse events were not significantly different between the 2 vaccine groups, and no serious vaccination-related adverse events were noted. In conclusion, the study vaccine exhibited substantial immunogenicity and safety in Korean children and is expected to be clinically effective.

Immunogenicity and safety of a tetravalent measles-mumps-rubella-varicella vaccine: an open-labeled, randomized trial in healthy Korean children.

PURPOSE: This study (NCT00751348) evaluated the immunogenicity and safety of a combined measles-mumps-rubella-varicella (MMRV) vaccine compared to co-administration of measles-mumps-rubella and varicella (MMR+V) vaccines in Korean children during their second year of life. MATERIALS AND METHODS: Healthy children aged 11-24 months received one dose of MMRV or MMR+V. Antibody titers against measles, mumps and rubella were measured using enzyme-linked immunosorbent assay and against varicella using an immunofluorescence assay. Parents/guardians recorded adverse events in diary cards for up to 43 days post-vaccination. The primary objective was to demonstrate non-inferiority of MMRV to MMR+V for all antigens in terms of seroconversion rates (SCRs), defined as a group difference with a lower limit of the 95% confidence interval (CI)>-10%. RESULTS: Of 474 subjects enrolled, 458 (MMRV, 301; MMR+V, 157) were included in the according-to-protocol cohort. For measles (98.0% vs. 99.4%), rubella (99.7% vs. 100%) and varicella (98.9% vs. 100%) SCRs, the lower limits of the 95% CIs for group differences were greater than -10%; however, for mumps SCRs (88.8% vs. 94.2%), it was -10.40%. The primary objective of non-inferiority in mumps SCRs was therefore not met, although the observed group difference in a post-hoc analysis of anti-mumps antibodies using a plaque reduction neutralization assay was 0.39% with a 95% CI lower limit of -4.03%. Adverse events occurred at comparable frequencies for both groups, except for more frequent fever in MMRV recipients. CONCLUSION: Based on the pre-specified non-inferiority criterion, SCRs of the MMRV vaccine were non-inferior to that elicited by MMR+V vaccines for all antigens except mumps.

Varicella and varicella vaccination in South Korea.

With continuing occurrence of varicella despite increasing vaccine coverage for the past 20 years, a case-based study, a case-control study, and an immunogenicity and safety study were conducted to address the impact of varicella vaccination in South Korea. Varicella patients under the age of 16 years were enrolled for the case-based study. For the case-control study, varicella patients between 12 months and 15 years of age were enrolled with one control matched for each patient. For the immunogenicity and safety study, otherwise healthy children from 12 to 24 months old were immunized with Suduvax (Green Cross, South Korea). Fluorescent antibody to membrane antigen (FAMA) varicella-zoster virus (VZV) antibody was measured before and 6 weeks after immunization. In the case-based study, the median age of the patients was 4 years. Among 152 patients between 1 and 15 years of age, 139 children received varicella vaccine and all had breakthrough infections. Clinical courses were not ameliorated in vaccinated patients, but more vaccinated patients received outpatient rather than inpatient care. In the case-control study, the adjusted overall effectiveness of varicella vaccination was 54%. In the immunogenicity and safety study, the seroconversion rate and geometric mean titer for FAMA antibody were 76.67% and 5.31. Even with increasing varicella vaccine uptake, we illustrate no upward age shift in the peak incidence, a high proportion of breakthrough disease, almost no amelioration in disease presentation by vaccination, and insufficient immunogenicity of domestic varicella vaccine. There is need to improve the varicella vaccine used in South Korea.

A randomized study of the immunogenicity and safety of Japanese encephalitis chimeric virus vaccine (JE-CV) in comparison with SA14-14-2 vaccine in children in the Republic of Korea.

A new live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) has been developed based on innovative technology to give protection against JE with an improved immunogenicity and safety profile. In this phase 3, observer-blind study, 274 children aged 12-24 months were randomized 1:1 to receive one dose of JE-CV (Group JE-CV) or the SA14-14-2 vaccine currently used to vaccinate against JE in the Republic of Korea (Group SA14-14-2). JE neutralizing antibody titers were assessed using PRNT50 before and 28 days after vaccination. The primary endpoint of non-inferiority of seroconversion rates on D28 was demonstrated in the Per Protocol analysis set as the difference between Group JE-CV and Group SA14-14-2 was 0.9 percentage points (95% confidence interval [CI]: -2.35; 4.68), which was above the required -10%. Seroconversion and seroprotection rates 28 days after administration of a single vaccine dose were 100% in Group JE-CV and 99.1% in Group SA14-14-2; all children except one (Group SA14-14-2) were seroprotected. Geometric mean titers (GMTs) increased in both groups from D0 to D28; GM of titer ratios were slightly higher in Group JE-CV (182 [95% CI: 131; 251]) than Group SA14-14-2 (116 [95% CI: 85.5, 157]). A single dose of JE-CV was well tolerated and no safety concerns were identified. In conclusion, a single dose of JE-CV or SA14-14-2 vaccine elicited a comparable immune response with a good safety profile. Results obtained in healthy Korean children aged 12-24 months vaccinated with JE-CV are consistent with those obtained in previous studies conducted with JE-CV in toddlers.

Current status of production and market of human vaccine products in Korea.

PURPOSE: The goal of this study was to build basic information related to the production and market of human vaccine products in Korea, which can be an important indicator to provide basic data in practical use. MATERIALS AND METHODS: Statistical data were obtained from the Bank of Korea, Korea Health Industry Development Institute, Korea Pharmaceutical Traders Association, and Korea Pharmaceutical Manufacturers Association. RESULTS: Vaccines are the 10th ranked drugs in the classification of whole complete preparated drugs. The production output of vaccines in Korea was 392.2 billion KRW in 2011, comprising 2.83% of complete preparated drug production output (13 trillion 880.8 billion KRW) and 2.54% of medical-pharmaceutical product output (15 trillion 440.3 billion KRW). The market scale of vaccines in Korea was 710 billion KRW in 2011, with an annual average growth rate of 11% in the past 6 years, comprising 2% of vaccine market in the world. There was also a significant increase in essential vaccines and other preventive vaccines in a global scale. CONCLUSION: Vaccines have the potential of becoming an emerging attractive industry. Based on the current analysis about the production of vaccine products and market scale, further development of the vaccine industry is expected in Korea.

Current status of registry of vaccine clinical trials conducted by Korean investigators in ClinicalTrials.gov, database of US National Institutes of Health.

PURPOSE: PubMed is not only includes international medical journals but also has a registration site for the ongoing clinical trials, such as ClinicalTrials.gov, under the supervision of US National Institutes of Health. We analyzed current status of vaccine clinical trials conducted by Korean investigators in database of ClinicalTrial.gov. MATERIALS AND METHODS: As of October 2012, there are total of 72 trials found on registry of vaccine clinical trials conducted by Korean investigators in database of ClinicalTrial.gov. These trials were analyzed and classified by conditions of vaccine clinical trials, biologicals or drugs used in vaccine clinical trials, status of proceeding research, and list of sponsor and collaborators. RESULTS: Total 72 trials of vaccine clinical trials conducted by Korean investigators are classified by groups of infection (64 trials), cancer (4 trials), and others (4 trials). Infections group shown are as follows: poliomyelitis, pertussis, diphtheria, tetanus, and Haemophilus influenzae type b (10), influenza (9), human papillomavirus infection (8), pneumococcal vaccine (6), herpes zoster (4), smallpox (4), hepatitis B (4), etc. One trial of each in lung cancer, breast cancer, prostate cancer, and colorectal cancer are shown in cancer group. One trial of each in Crohn's disease, ulcerative colitis, renal failure, and rheumatoid arthritis are shown in other group. CONCLUSION: Vaccine clinical trials conducted by Korean investigators in ClinicalTrial.gov reflects the current status of Korean research on vaccine clinical trials at the international level and can indicate research progress. It is hoped that this aids the development of future vaccine clinical trials in Korea.

The history of vaccination and current vaccination policies in Korea.

There may be many reasons for the significant decrease in the incidence of the pediatric infectious diseases in modern Korea; this could be due to the improvement of sanitary facilities, significant growth of Korean economy, improvement of nutrition, development and dissemination of antibiotics and implantation of vaccination, and overall improvement of medical technology. The development of vaccination has been highlighted as a striking achievement of the modern medical sciences with new technologies in many fields of medicine. Since 1876, the method for vaccination has opened its new era by Suk-Young Jee, known as the Jenner in Korea who wrote a book about smallpox vaccination, and it led an opportunity to propagate the needs for the vaccination in Korea. There was a time when pediatric wards were full of patients with parasitic diseases and many vaccine-preventable diseases such as diphtheria, pertussis, Japanese B encephalitis, and poliomyelitis in 1950s-1960s. We do not see those infectious diseases that often any more in recent years. However, we still have patients with water-borne diseases and other communicable diseases related to increasing international travels. We just experienced the first pandemic influenza of the 21st century in 2009 and avian influenza is still a threat to humans in other parts of the world with an unpredictable potential of pandemicity. In addition, we have tough battles with emerging antibiotic resistance in many strains of bacteria and increased opportunistic infections due to improvement of medical technology involving more aggressive treatment modality and use of medical devices. Researches in many areas are under way and we hope that some of them may be preventable and decreased with a development of new vaccines in the future.