Introduction: Community-acquired pneumonia remains to be an important cause of morbidity and mortality among the pediatric age group with Streptococcus pneumoniae and Haemophilus influenzae typ B being the predominant bacteria identified. Conjugate vaccines against these organisms are available however, the prevalence of pneumonia in our country continues to be high. Objectives: The aim of this research is to determine the HiBCV and PCV 7 immunization status of children 5 years and below who were hospitalized due to pneumonia compared to controls. This study also aims to describe the clinical outcome of pneumonia among children who were vaccinated with HiBCV and/or PCV7 compared to those without vaccination. Methods: This retrospective case-control study was conducted in Makati Medical Center from January 1, 2009 to August 31, 2010. Cases were children five years old and below discharged with the final diagnosis of pneumonia. Controls were patients five years and below discharged without pneumonia during the same study period. Medical records were reviewed for information on age, gender, clinical findings upon admission, laboratory results, vaccination status, interventions and outcomes. Conclusion: The findings indicated that clinical and radiologically-confirmed pneumonia still occurred among children with complete vaccination with HiBCV and PCV7. Although not statistically significant, those without vaccination had higher odds of having pneumonia.
Human ; Male ; Female ; Child Preschool ; Infant ; HAEMOPHILUS INFLUENZAE TYPE B ; VACCINES, CONJUGATE ; HEPTAVALENT PNEUMOCOCCAL CONJUGATE VACCINE ; IMMUNIZATION ; PNEUMONIA

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 > or =0.35 microg/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 (> or =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.
Aged ; Antibodies ; Antibody Formation ; Child ; Enzyme-Linked Immunosorbent Assay ; Homicide ; Humans ; Immunization ; Pneumococcal Vaccines ; Streptococcus pneumoniae ; Vaccination ; Heptavalent Pneumococcal Conjugate Vaccine

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.
Adult ; Aged ; Antibodies ; Child ; Cross Protection ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Homicide ; Humans ; Immunization ; Immunization, Secondary ; Immunoglobulin G ; Immunoglobulin M ; Pneumococcal Vaccines ; Streptococcus pneumoniae ; Heptavalent Pneumococcal Conjugate Vaccine

Streptococcus pneumoniae is a major etiology of serious bacterial infection among children worldwide. Among the 91 serotypes, the majority of invasive infections are caused by 10 common serotypes, 14, 16, 18, 19, 23, 4, 9, 7, 1, and 3. However, the ranking and serotype prevalence differ by age group and country. The heptavalent 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 by the vaccine serotypes among the vaccines (direct effect). However, it is notable that substantial declines in invasive diseases among older children and adults ensued through indirect effects on transmission (i.e., herd immunity). 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 invasive disease, nasopharyngeal colonization, and antibiotic resistance patterns. In contrast, there is a small increase in the number of invasive diseases caused by nonvaccine serotypes, so called 'replacement phenomenon', though it is still minor compared with overall declines of vaccine-serotype diseases. Of those, the increase in the 19A-related disease has become most prominent. In Korea, a remarkable increase of 19A was noted before the introduction of PCV7. The emergence of resistance and replacement of disease by nonvaccine strains should be closely monitored.
Adult ; Bacterial Infections ; Child ; Colon ; Drug Resistance, Microbial ; Heptavalent Pneumococcal Conjugate Vaccine ; Humans ; Immunization ; Incidence ; Infant ; Korea ; Nasopharyngeal Diseases ; Pneumococcal Vaccines ; Prevalence ; Streptococcus pneumoniae ; Vaccines

Although it is well known that pneumococcal conjugate vaccines provide cross-protection against some vaccine-related serotypes, these mechanisms are still unclear. This study was performed to investigate the role of cross-protective IgM antibodies against vaccine-related serotypes 6A, 6C, and 19A induced in children aged 12-23 months after immunization with 7-valent pneumococcal conjugate vaccine (PCV7). We obtained serum samples from 18 Korean children aged 12-23 months after a PCV7 booster immunization. The serum IgG and IgM concentrations of serotypes 6B and 19F were measured by enzyme-linked immunosorbent assay (ELISA) in serum. The opsonic indices (OIs) against vaccine serotypes 6B and 19F and vaccine-related serotypes 6A, 6C, and 19A were determined by an opsonophagocytic killing assay (OPA) in IgM-depleted and control serum. Both IgG and IgM antibodies in ELISA and opsonic indices in OPA against serotypes 6B and 19F were demonstrated in the immune serum. IgM depletion decreased the OIs against vaccine serotypes 6B (geometric means of OIs (GMIs) of 3,009 vs. 1,396, 38% reduction) and 19F (1,117 vs. 750, 36% reduction). In addition, IgM depletion markedly decreased the OIs against vaccine-related serotypes 6A (GMIs of 961 vs. 329, 70% reduction), 6C (432 vs. 185, 72% reduction), and 19A (301 vs. 166, 58% reduction). The booster immunization PCV7 induced protective antibodies in the form of both IgG and IgM isotypes. IgM antibodies contributed to eliciting cross-protection against vaccine-related serotypes as well as against vaccine serotypes.
Antibodies, Bacterial/blood ; Antibodies, Neutralizing/blood ; Enzyme-Linked Immunosorbent Assay ; Heptavalent Pneumococcal Conjugate Vaccine/*immunology ; Humans ; Immunoglobulin M/*blood ; Infant ; Pneumococcal Infections/*prevention & control ; Pneumococcal Vaccines/*immunology ; Serogroup ; Streptococcus pneumoniae/immunology

The purpose of this study was to investigate the association between asthma and invasive pneumococcal disease (IPD) in Korea. A retrospective population-based cohort study was conducted using the Korean Health Insurance Review and Assessment database 2010-2011. The subjects included 935,106 (2010) and 952,295 (2011), of whom 398 (2010) and 428 (2011) patients with IPD were identified. There was significant difference in the prevalence of IPD in patients with and without asthma (0.07% vs. 0.02% in 2010 and 0.08% vs. 0.01% in 2011; P<0.001). After adjusting for age and gender, patients with asthma showed over a three-fold increased risk of IPD compared with patients without asthma (adjusted odds ratio [aOR] 3.90, 95% confidence interval [CI] 3.02-5.03 in 2010 / aOR, 5.44; 95% CI, 4.10-7.22 in 2011; P<0.001). These findings were also significant in children (aOR, 2.08; 95% CI, 1.25-3.45 in 2010; P=0.005 / aOR, 3.26; 95% CI, 1.74-6.11 in 2011; P<0.001). Although diabetes mellitus was also significantly associated with IPD, relatively low ORs compared with those of asthma were noted (aOR, 1.85; 95% CI, 1.35-2.54 in 2010 / aOR, 2.40; 95% CI, 1.78-3.24 in 2011; P<0.001). Both children and adults with asthma are at increased risk of developing IPD.
Adolescent ; Adult ; Aged ; Asthma/complications/*epidemiology ; Child ; Cohort Studies ; Diabetes Mellitus/epidemiology ; Heptavalent Pneumococcal Conjugate Vaccine/immunology ; Humans ; Immunologic Deficiency Syndromes/complications/*epidemiology ; Middle Aged ; Pneumococcal Infections/complications/*epidemiology ; Pneumococcal Vaccines/immunology ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; Streptococcus pneumoniae/pathogenicity ; Young Adult