Polyvalent Pneumococcal Vaccine Research Articles

Fever Without Source in Unvaccinated Children Aged 3 to 24 Months: What Workup Is Recommended?

Fever is the most common complaint for infants and children brought to the emergency department. Most febrile children younger than 3 years will have a clinically apparent source of infection. However, in approximately 20% of these children, a source cannot be identified by history and physical examination alone. The recommended diagnostic approach to children younger than 3 years presenting with fever without source (FWS) has changed dramatically over the past 30 years because of the widespread use of the Haemophilus influenza type b and polyvalent pneumococcal vaccines. The percentage of children in the United States unvaccinated at 24 months is now over 1% and seems to be increasing. This article will review what is currently known about FWS in children aged 3 to 24 months in the modern era and how it pertains to unvaccinated children treated in the emergency department. An algorithm for the treatment of unvaccinated young children presenting with FWS is proposed.

PCR and Culture Analysis of Streptococcus pneumoniae Nasopharyngeal Carriage in Healthy Children.

Invasive Streptococcus pneumoniae disease is preceded by asymptomatic nasopharyngeal carriage. Measuring carriage in healthy populations provides data on what serotypes are present in communities, which is of interest in the era of polyvalent pneumococcal conjugate vaccines. Nasopharyngeal swabs from a survey of 682 and 800 healthy children in 2016 and 2018, respectively, were analyzed by culture and Quellung reaction to determine rates of carriage and serotypes. All swabs from 2016 and 300 randomly selected swabs from 2018 were then analyzed using real-time semi-quantitative PCR (qPCR) to detect S. pneumoniae gene targets lytA, piaA, and SP2020 and determine serotype. There were 71 (10.4%) and 68 (8.5%) culture positive samples in 2016 and 2018, respectively. All of these were also positive by qPCR except one that was equivocal. In total, 46.0% of 2016 swabs were positive by qPCR. In 2018, results from the selected sample extrapolated to the complete sample showed 49.0% positive by qPCR. PCV13 serotypes were detected in 29.3% and 21.7% of S. pneumoniae qPCR positive samples from 2016 and 2018, respectively; compared with only 8.4% and 6.0% PCV13 serotypes detected by Quellung reaction in culture positive samples. Compared with culture, qPCR detected S. pneumoniae more frequently. Further, qPCR serotyping detected PCV13 serotypes in a larger proportion of samples than culture and Quellung reaction did, showing that, despite established universal childhood PCV13 immunization, vaccine serotypes can still be detected in a large proportion of young children.

Splenectomy and distal pancreatectomy in advanced ovarian cancer.

Splenectomy or distal pancreatectomy (DP) is sometimes performed for optimal cytoreduction in advanced ovarian cancer (AOC). In particular, it is considered to remove tumors involving the splenic hilum or the capsule of the spleen to secure tumor-free margins sufficiently. For splenectomy, the gastro-splenic ligament is opened, and the short gastric vessels are dissected. After the splenocolic ligament and splenic flexure of the colon are transected, the peritoneal attachments, including the splenorenal and splenophrenic ligaments, are divided to mobilize the spleen, and then the splenic artery and vein are identified and ligated separately. If DP is needed for en bloc resection of tumors, a linear cutting stapler is used to remove the tail of the pancreas, and suture reinforcement with 2-0 or 3-0 prolene on the cut section of the pancreas is performed to prevent postoperative pancreatic fistula (POPF). Immunization with a polyvalent pneumococcal vaccine is required after splenectomy to avoid overwhelming post-splenectomy infection (OPSI) caused by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. If POPF occurs after splenectomy or DP, continued drainage with close monitoring is needed with the administration of board spectrum antibiotics in grade A or B POPF according to the criteria of the International Study Group of Pancreatic Fistula (ISGPF). In contrast, grade C POPF requires aggressive management using nothing by mouth, total parenteral nutrition, and somatostatin analogs, and sometimes reoperation if deteriorating signs such as sepsis and organ dysfunction. Thus, the effort for preserving pancreatic tail is needed to reduce hospitalization and the risk of POPF despite the minimal impact of DP on the success rate of optimal cytoreduction.

Infections Due to Streptococcus pneumoniae

Pneumococci, or Streptococcus pneumoniae, are gram-positive, lancet-shaped diplococci but may also grow in short chains. The polysaccharide polymer that forms the outer capsule of S pneumoniae is chemically and antigenically unique and is crucial to virulence. There are at least 90 distinct serotypes. The capsule allows the bacteria to resist phagocytosis by leukocytes unless the organisms have been opsonized by antibody or serum complement components. Certain pneumococcal serotypes, such as the heavily encapsulated type 3 pneumococcus, are particularly virulent. In fact, only 23 serotypes account for 80% of bacteremic pneumococcal infections in the United States; capsular polysaccharides from these 23 serotypes are incorporated into the polyvalent polysaccharide pneumococcal vaccine (PPSV23), which has been available since 1983. This review covers the epidemiology and pathogenesis of pneumococcal infections, clinical pneumococcal infections, and prevention of pneumococcal infections. Adverse outcomes in pneumococcal pneumonia, antibiotic treatment for penicillin-resistant S pneumoniae, and Centers for Disease Control and Prevention child and adolescent immunization schedules are discussed. This review contains 1 figure, 6 tables, and 41 references. Key words: bacterial pneumonia, PCV13, penicillin-resistant Streptococcus pneumoniae, pneumococcal pneumonia, pneumococcus, PPSV23, pneumonia vaccine, Streptococcus pneumoniae

A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host

Chemical synthesis of conjugate vaccines, consisting of a polysaccharide linked to a protein, can be technically challenging, and in vivo bacterial conjugations (bioconjugations) have emerged as manufacturing alternatives. Bioconjugation relies upon an oligosaccharyltransferase to attach polysaccharides to proteins, but currently employed enzymes are not suitable for the generation of conjugate vaccines when the polysaccharides contain glucose at the reducing end, which is the case for ~75% of Streptococcus pneumoniae capsules. Here, we use an O-linking oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end. In addition, we show that different vaccine carrier proteins can be glycosylated using this system. Pneumococcal bioconjugates are immunogenic, protective and rapidly produced within E. coli using recombinant techniques. These proof-of-principle experiments establish a platform to overcome limitations of other conjugating enzymes enabling the development of bioconjugate vaccines for many important human and animal pathogens.

Review: In COPD, injectable polyvalent pneumococcal vaccines reduce risk for community-acquired pneumonia.

Source Citation Walters JA, Tang JN, Poole P, Wood-Baker R. Pneumococcal vaccines for preventing pneumonia in chronic obstructive pulmonary disease. Cochrane Database Syst Rev. 2017;1:CD001390. 281...

Pneumococcal vaccines for preventing pneumonia in chronic obstructive pulmonary disease.

People with chronic obstructive pulmonary disease (COPD) are at increased risk of pneumococcal disease, especially pneumonia, as well as acute exacerbations with associated morbidity and healthcare costs. To determine the efficacy of injectable pneumococcal vaccination for preventing pneumonia in persons with COPD. We searched the Cochrane Airways COPD Trials Register and the databases CENTRAL, MEDLINE and Embase, using prespecified terms. Searches are current to November 2016. We included randomised controlled trials (RCT) comparing injectable pneumococcal polysaccharide vaccine (PPV) or pneumococcal conjugated vaccine (PCV) versus a control or alternative vaccine type in people with COPD. We used standard Cochrane methodological procedures. For meta-analyses, we subgrouped studies by vaccine type. For this update, we added five studies (606 participants), meaning that the review now includes a total of 12 RCTs involving 2171 participants with COPD. Average age of participants was 66 years, male participants accounted for 67% and mean forced expiratory volume in one second (FEV1) was 1.2 L (five studies), 54% predicted (four studies). We assessed risks of selection, attrition and reporting bias as low, and risks of performance and detection bias as moderate.Compared with control, the vaccine group had a lower likelihood of developing community-acquired pneumonia (CAP) (odds ratio (OR) 0.62, 95% confidence interval (CI) 0.43 to 0.89; six studies, n = 1372; GRADE: moderate), but findings did not differ specifically for pneumococcal pneumonia (Peto OR 0.26, 95% CI 0.05 to 1.31; three studies, n = 1158; GRADE: low). The number needed to treat for an additional beneficial outcome (NNTB) (preventing one episode of CAP) was 21 (95% CI 15 to 74). Mortality from cardiorespiratory causes did not differ between vaccine and control groups (OR 1.07, 95% CI 0.69 to 1.66; three studies, n = 888; GRADE: moderate), nor did all-cause mortality differ (OR 1.00, 95% CI 0.72 to 1.40; five studies, n = 1053; GRADE: moderate). The likelihood of hospital admission for any cause, or for cardiorespiratory causes, did not differ between vaccine and control groups. Vaccination significantly reduced the likelihood of a COPD exacerbation (OR 0.60, 95% CI 0.39 to 0.93; four studies, n = 446; GRADE: moderate). The NNTB to prevent a patient from experiencing an acute exacerbation was 8 (95% CI 5 to 58). Only one study (n = 181) compared the efficacy of different vaccine types - 23-valent PPV versus 7-valent PCV - and reported no differences for CAP, all-cause mortality, hospital admission or likelihood of a COPD exacerbation, but investigators described a greater likelihood of some mild adverse effects of vaccination with PPV-23. Injectable polyvalent pneumococcal vaccination provides significant protection against community-acquired pneumonia, although no evidence indicates that vaccination reduced the risk of confirmed pneumococcal pneumonia, which was a relatively rare event. Vaccination reduced the likelihood of a COPD exacerbation, and moderate-quality evidence suggests the benefits of pneumococcal vaccination in people with COPD. Evidence was insufficient for comparison of different pneumococcal vaccine types.

Evaluation of quality of life and prognostic scales in patients with chronic obstructive pulmonary disease

This study was aimed at assessment of vaccination effects on quality of life and main prognostic scores in COPD patients. Methods . The study involved 362 male patients with COPD. Vaccination was done using13-valent conjugate pneumococcal vaccine Prevenar-13 (PCV-13) and polyvalent pneumococcal vaccine Pneumo-23 (PPV23). Quality of life was assessed using the Russian version of SRGQ and CAT questionnaire. Prognostic BODE, DOSE and ADO scores were calculated. Results. Vaccination with PCV13 and PPV23 was associated with improvement in quality of life in 1 year after vaccination, though this effect of PPV23 decreased to the 3 rd year. Quality of life questionnaires help to assess the therapeutic strategy chosen both in early and delayed follow-up. BODE, DOSE, and ADO scores have demonstrated a reliable and statistically significant decrease in 1 year after vaccination; for PCV13, this effect maintained in 3 years after vaccination. Conclusion . Vaccination with PCV13 could reduce total 3-year healthcare expenses to 11,357 RUB (78%), partly due to long-term maintenance of the effect of vaccination. This is an important advantage of PCV13 over PPV23 both from economic and clinical points of view.

Selective Subnormal IgG1 in 54 Adult Index Patients with Frequent or Severe Bacterial Respiratory Tract Infections.

We characterized 54 adult index patients with reports of frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG1. Mean age was 50 ± 13 (SD) y; 87.0% were women. Associated disorders included the following: autoimmune conditions 50.0%; hypothyroidism 24.1%; atopy 38.9%; and other allergy 31.5%. In 35.5%, proportions of protective S. pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination (PPPV). Blood lymphocyte subset levels were within reference limits in most patients. Regressions on IgG1 and IgG3 revealed no significant association with age, sex, autoimmune conditions, hypothyroidism, atopy, other allergy, corticosteroid therapy, or lymphocyte subsets. Regression on IgG2 revealed significant associations with PPPV response (negative) and CD19+ lymphocytes (positive). Regression on IgG4 revealed significant positive associations with episodic corticosteroid use and IgA. Regression on IgA revealed positive associations with IgG2 and IgG4. Regression on IgM revealed negative associations with CD56+/CD16+ lymphocytes. Regressions on categories of infection revealed a negative association of urinary tract infections and IgG1. HLA-A⁎03, HLA-B⁎55 and HLA-A⁎24, HLA-B⁎35 haplotype frequencies were greater in 38 patients than 751 controls. We conclude that nonprotective S. pneumoniae IgG levels and atopy contribute to increased susceptibility to respiratory tract infections in patients with selective subnormal IgG1.

Selective subnormal IgG3 in 121 adult index patients with frequent or severe bacterial respiratory tract infections

We characterized 121 adults with frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG3. Mean age was 47±13 (SD)y; 87.6% were women. Associated disorders included: autoimmune conditions 33.1%; hypothyroidism 14.9%; atopy 29.8%; and other allergy manifestations 41.3%. In 34.1%, proportions of protective Streptococcus pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination. Blood CD19+, CD3+/CD4+, CD3+/CD8+, and CD56+/CD16+ lymphocyte levels were within reference limits in most patients. In regression analyses, independent variables age; sex; autoimmune conditions; hypothyroidism; atopy; allergy manifestations; corticosteroid therapy; and lymphocyte subsets were not significantly associated with IgG subclass, IgA, or IgM levels. Frequencies of HLA haplotypes A*01, B*08; A*02, B*14; A*02, B*15; A*02, B*44; A*02, B*57; and A*03, B*07 were greater in 80 patients than 751 controls. We conclude that subnormal IgG3 and non-protective S. pneumoniae IgG levels contribute to increased susceptibility to respiratory tract infections.

ABSTRACT 427

Background and aims: Streptococcus pneumoniae (SP or pneumococcus) causes many childhood diseases and is a significant cause of morbidity and mortality in children worldwide. Invasive pneumococcal disease could result in death or permanent disabilities despite treatment with systemic antibiotics. Aims: To investigate the pattern of morbidity and mortality associated with severe SP infection and pediatric intensive care unit (PICU) admission. Methods: A retrospective study between 2002 and 2013 of all children in the PICU with a laboratory isolation of SP. Results: There were 20 (1.2%) PICU patients with SP isolations [blood culture (n=6 patients), CSF (n=1) and pleural/pulmonary specimens (n=13)]. 90% of SP were sensitive to penicillin, and all SP specimens were sensitive to cefotaxime and vancomycin. SP infections were associated with high PICU mortality of 25% (or 5% of total PICU mortality), high rates of need for mechanical ventilatory (65%), inotropic supports (35%) and dialysis (15%), and an odds of PICU deaths of 5.96 (p=0.0008). Older children had significantly higher prevalence of premorbid conditions such as malignancy, mental retardation/cerebral palsy (MRCP)+/-seizure disorders, chromosomal or genetic disorders (p=0.003) than children < 5 years of age. Serotypes were available for some of these specimens which included 19A, 19F, 6B, 3 and 6C. There were 4 deaths with multi-organ system failure and hemolytic uremic syndrome (two 19A, and two serotype 3). Conclusions: Severe SP infections are associated with significant morbidity and mortality despite treatment with systemic antibiotics and ICU support. The expanded coverage of newer polyvalent pneumococcal vaccines can probably prevent infections by serotypes 19A, 6B and 3.

Cardiopulmonary morbidity of streptococcal infections in a PICU

The streptococci are important bacteria that cause serious childhood infections. We investigated cardiopulmonary morbidity associated with streptococcal infection and pediatric intensive care unit (PICU) admission. A retrospective study between 2002 and 2013 of all children with a laboratory isolation of streptococcus. There were 40 (2.3%) PICU patients with streptococcal isolations including Streptococcus pyogenes (Group A streptococcus, GAS, n = 7), Streptococcus agalactiae (Group B streptococcus, GBS, n = 5), Streptococcus pneumoniae (SP, n = 20), alpha-hemolytic (n = 4), beta-hemolytic (n = 2) and gama-hemolytic (n = 2) streptococci. Comparing among GAS, GBS and SP, respiratory isolates were more likely positive for GAS or SP (P = 0.033), whereas cerebrospinal fluid was more likely positive for GBS (P = 0.002). All GAS and GBS, and the majority of SP (90%) were sensitive to penicillin. All SP specimens were sensitive to cefotaxime and vancomycin. These infections were associated with high PICU mortality of 43%, 20% and 25%, respectively. Isolation of streptococci was associated with a 30% mortality and high rates of need for mechanical ventilatory and inotropic supports. Patients with GAS, SP or any streptococcal isolation had relative risks [95% confidence interval (CI), P value] of PICU deaths of 7.5 (CI 3.1-18.1, P < 0.0001), 4.5 (CI 2.0-9.8, P < 0.0002) and 5.7 (CI 3.4-9.5, P < 0.0001), respectively. In SP, older children had significantly higher prevalence of premorbid conditions such as malignancy, mental retardation/cerebral palsy ± seizure disorders, chromosomal or genetic disorders (P = 0.003) than children <5 years of age. Serotypes were available for some of these specimens that included 19A, 6B, 3 and 6C. There were four SP deaths with multiorgan system failure and hemolytic uremic syndrome (two 19A and two serotype 3). Severe streptococcal infections are associated with significant morbidity and mortality despite treatment with systemic antibiotics and intensive care unit support. GAS and SP affect the lungs of children, whereas GBS more likely causes meningitis in infants. The expanded coverage of newer polyvalent pneumococcal vaccines can probably prevent infections by serotypes 19A, 19F, 6B and 3.

Maximizing the impact of antimicrobial stewardship

The decline in the development and approval of new antimicrobial agents, especially those with activity against multidrug-resistant Gram-negative bacteria, has arisen as one of the major public health threats of the 21st century. Antimicrobial stewardship has emerged as a key available means to attenuate this threat. Because of the immediacy of the crisis imposed by the dearth of new antimicrobial agents, this review aims to seek out innovative mechanisms that could complement existing programmes to maximize their effectiveness. Provision of expedited microbiological identification and susceptibility profiles utilizing molecular diagnostic techniques are means that are showing promise in complementing existing stewardship interventions. Biomarkers such as procalcitonin that facilitate clinical decision-making processes in discriminating between noninfectious causes masquerading as sepsis can assist in withholding or earlier discontinuation of antimicrobial agents. Seasonal influenza and polyvalent pneumococcal vaccine have a role to play by preventing secondary bacterial infections. Electronic learning tools are a means of disseminating information rapidly and universally. Coordinated national and international stewardship efforts play an essential role in promotion, engaging the public, and ensuring provision of sufficient resources. The safeguarding of antimicrobial agents for future generations is necessary, if we as a public do not wish to face a world without antibiotics. All potentially available resources must be recruited to order to protect antimicrobials. Robust methods of evaluating each of these interventions needs to be included from inception to evaluate which strategies are the most effective.

SAT0066 Routine Preventative Vaccinations in Patients with Long-Standing Rheumatoid Arthritis Receiving Adalimumab

BackgroundAdalimumab (ADA) has been shown to be safe and effective in patients (pts) with long-standing rheumatoid arthritis (RA).1 Patients with RA are candidates for routine vaccination with inactivated agents, in...

Immune Response Post-Administration of Polyvalent Pneumococcal Vaccine and Implications Regarding Clinical Efficacy

Immune Response Post-Administration of Polyvalent Pneumococcal Vaccine and Implications Regarding Clinical Efficacy

Prevalence of Pneumococcal Bacteremia in Children with Sickle Cell Disease Hospitalized for Management of a Febrile Illness

AbstractAbstract ▪3214▪This icon denotes a clinically relevant abstract Introduction:Children with sickle cell disease are at a high risk of death from pneumococcal bacteremia due to functional asplenia. The common practice for management of any fever in a child with sickle cell disease is in-patient antibiotic therapy for presumed bacteremia, until the blood cultures have remained negative for 48 hours. We hypothesize that interventions such as penicillin prophylaxis, use of polyvalent pneumococcal vaccine at 2 years of age in addition to the primary immunization series with pneumococcal conjugate vaccine 13 have decreased the prevalence of pneumococcal bacteremia in children with sickle cell disease. Outpatient management of an uncomplicated febrile illness may be a safe alternative. Methods:We conducted a retrospective chart review of children with sickle cell disease hospitalized with a fever at Children's and Women's Hospital between January 2006 and June 2012. We collected demographical parameters, temperature, white blood cell count and C-reactive protein level at the time of presentation as possible predictors of true bacteremia. The continuous variables were compared between the two groups (positive and negative blood cultures) using independent t-test. We also recorded the time to positivity of blood cultures, pathogens identified in positive blood cultures, serotypes and sensitivities of pneumococcal bacteria. Results:A total of 133 patients, aged 2 months to 18 years, met the inclusion criteria with 456 hospital admissions. The prevalence of culture proven bacteremia was 3.7% with only two (0.44%) cases of pneumococcal bacteremia. We have not had any patient with pneumococcal bacteremia reported since the start of pneumococcal conjugate vaccine 13, in May 2010. Both the patients with pneumococcal bacteremia were older than five years and had discontinued taking penicillin prophylaxis. The first patient was fully vaccinated with pneumococcal conjugate vaccine 7 but had not received polyvalent vaccine. She contracted a non-vaccine serotype (23B) that was susceptible to penicillin, ceftriaxone, and vancomycin. The second patient was partially vaccinated and acquired a serotype (23F) that is included in pneumococcal conjugate vaccine 7. The bacterium was resistant to penicillin but sensitive to ceftriaxone and vancomycin. In the analysis of predictors of bacteremia, the average C-reactive protein level was found to be 6.3mg/dL in patients with positive blood cultures and 4.5mg/dL in patients with negative blood cultures (p=0.02). The mean age of patients with positive blood cultures was 11 years compared to 7.4 years in patients with negative blood cultures (p=0.03). The differences in body temperature and white blood cell count between the two groups were not statistically significant. The average time to positivity measured from the time of collection was 25.4 hours. Discussion:Penicillin prophylaxis and complete immunization, in accordance with the centers for disease control and prevention guidelines are important for patients with sickle cell disease. Patients with an uncomplicated febrile illness may not necessarily need to be hospitalized to continue antibiotics. We support an outpatient care model proposed by Williams et al, comprising of a single 24-hour dose of ceftriaxone followed by oral cefixime for 5 days and follow-up telephone calls by a nurse. Good patient education may help ensure compliance with outpatient care. Outpatient management of an uncomplicated febrile illness will be more cost-effective and beneficial to the patients and families. With this approach, however, patients may not be fully protected against ceftriaxone resistant pneumococccal infections. Bacterial resistance patterns in the community should be brought under consideration when implementing such a model. Conclusion:The prevalence of pneumococcal bacteremia in children with sickle cell disease has decreased in the past few years. In our analyses, we found older age and an elevated C-reactive protein level to be statistically significant predictors of a positive blood culture. Disclosures:No relevant conflicts of interest to declare.

Streptococcus vaccination and MRSA

586 www.thelancet.com/infection Vol 12 August 2012 Several studies have shown that nasopharyngeal carriage of vaccine-type S pneumoniae strains is negatively associated with Staphylococcus aureus carriage in the nasopharynx. Selva and co-workers described an antistaphylococcal mechanism whereby S pneumoniae kills S aureus by producing hydrogen peroxide. van Gils and colleagues report that use of the vaccine increased carriage of S aureus in a cohort of Dutch children. Could use of polyvalent pneumococcal vaccines be driving the increased incidence of community-acquired meticillin-resistant S aureus (MRSA) infection? Although Miller and colleagues did describe S pneumoniae serotype replacement, they did not investigate S aureus carriage. To show a negative association between S pneumoniae and S aureus carriage in a UK cohort of heptavalent pneumococcal conjugate vaccine recipients would be useful. Further studies should explore the link between vaccination and staphylococcal disease, both in vaccine recipients and the people they contact. Meticillin-resistant and meticillin-sensitive strains should be distinguished in investigations of S aureus carriage. The Panton-Valentine leukocidin status of the isolate should also be investigated because it is linked epidemiologically with communityacquired MRSA infection. These data would help to clarify any role that pneumococcal vaccines might have in S aureus infection.

Clinical features of community-acquired pneumonia in servicemen after pneumococcal vaccination

Summary. The study involved 2,000 army conscripts with community-acquired pneumonia (CAP). Clinical and laboratory features of CAP were studied in 693 patients who had been previously vaccinated with polyvalent polysaccharide pneumococcal vaccine "Pneumo-23" (Aventis Pasteur SA, France) and in 1307 patients of the control group. The incidence of severe CAP in vaccinated patients was 2.2-fold and the incidence of moderate CAP was 1.2-fold lower compared to unvaccinated patients. On the contrary, a mild CАP prevalence was 1.3-fold higher in vaccinated patients. The vaccinated patients had complication rate twice as lower and more rapid resolution of clinical and radiological signs of CAP.

Childhood Pneumococcal Diseases and Serotypes: Can Vaccines Protect?

To describe pneumococcal diseases in pediatric intensive care unit (PICU) and non-PICU patients. The clinical, serotypes, and antibacterial sensitivity patterns of all children admitted to the pediatric wards (including PICU) of a university-affiliated teaching hospital from 2007 through 2009 with pneumococcal isolates were reviewed. Twelve cases of pneumococcal disease in children from 2007 through 2009 were reported. Five patients were admitted to PICU and 7 were general pediatric admissions. Four patients (2 PICU and 2 general pediatric) had received full or partial 7-valent pneumococcal vaccinations. All four patients recovered following systemic antibiotic treatment without sequelae. The serotypes of all PICU and some general pediatric cases were available and included 3, 6B, 19A and 19F. All isolates were sensitive to vancomycin. 50% were intermediate resistant/resistant to penicillin and 17% resistant to cefotaxime. PICU cases required longer total hospital stay (23 days vs 5 days, p=0.013). Three patients were ventilated and one received inotropic support. There was no death in this series. Pneumococcal disease may develop despite prior vaccination. The expanded coverage of newer polyvalent pneumococcal vaccines might have prevented some, but not all, of these admissions.

The early kinetics of circulating pneumococcal-specific memory B cells following pneumococcal conjugate and plain polysaccharide vaccines in the elderly

In young children, polyvalent pneumococcal polysaccharide conjugate vaccines (PCVs) have been shown to offer advantage over plain polysaccharide vaccines (PPVs) in both immunogenicity and priming for memory responses. In the elderly, the potential benefit of conjugate vaccines is unclear. Here, we explore the early kinetics of serum antibody and circulating plasma and memory B cell responses to pneumococcal capsular polysaccharide (PPS) in older adults ( n = 37) immunised a PPV vaccine, Pneumovax™ or a PCV: Prevenar™. All individuals had serum evidence of pre-existing serotype-specific immunity. Following immunisation, a day 7 rise in circulating PPS-specific plasma and memory antibody secreting cells (AbSCs) was detected in both vaccine groups and this was sustained to day 28 in some PCV recipients. There was no difference between vaccine groups in serum antibody responses or the kinetics of the early PBMC-derived B cell responses. Although our sample cohort was small, these data are different from profiles in younger individuals at early time points post-immunisation and suggest that pneumococcal conjugate vaccines may not quantitatively enhance the generation of memory responses in the elderly.