Efficacy of a pneumococcal conjugate vaccine against acute otitis media

Anticipated Effects of Higher-valency Pneumococcal Conjugate Vaccines on Colonization and Acute Otitis Media

BACKGROUND

Bacterial etiologies of acute otitis media (AOM) have shifted from the introduction of pneumococcal conjugate vaccines (PCVs), antibiotic selection and competition among species. We characterized Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hflu) and Moraxella catarrhalis (Mcat) in the nasopharynx during well-child healthy visits and at the onset of AOM, and in middle ear fluid (MEF) of children with AOM to assess anticipated effects of higher-valency PCVs (PCV15 and PCV20).

METHODS

From September 2021 to September 2023, we conducted a prospective longitudinal cohort study of PCV13 immunized children 6-36 months old. MEF was collected via tympanocentesis. Serotyping and antibiotic susceptibility testing were performed on Spn, Hflu and Mcat isolates.

RESULTS

We obtained 825 nasopharyngeal and 216 MEF samples from 301 children. The order of frequency of nasopharyngeal colonization was Mcat, Spn and Hflu; Hflu was the predominant otopathogen in MEF. Among Spn isolates, non-PCV15, non-PCV20 serotypes predominated in the nasopharynx and in MEF; the most frequent serotype was 35B. Among MEF samples, 30% of Spn isolates were amoxicillin nonsusceptible; 23% of Hflu isolates and 100% of Mcat isolates were β-lactamase-producing.

CONCLUSION

The majority of Spn isolates among young children were non-PCV15, non-PCV20 serotypes, especially serotype 35B; therefore, the impact of higher-valency PCVs in reducing pneumococcal colonization or AOM is expected to be limited. Hflu continues to be the most frequent AOM pathogen. Antibiotic susceptibility data suggest a high dose of amoxicillin/clavulanate or alternative drugs that are effective against contemporary mix of otopathogens could be considered for optimal empiric selection to provide the best efficacy.

Exploring the OTITIS Research Landscape Through a Scientometric Approach

Otitis media is a common health problem affecting people of all ages and significantly impacting public health and healthcare costs. Otitis media, a type of middle ear disease, is one of the most common types. This scientometric study aimed to provide an overview of the knowledge domain in otitis media research. Documents were retrieved from the Web of Science database. A scientometric study was then performed on a sample of 27,213 documents. This study found that research on otitis media has increased significantly in recent years, with an annual growth rate of 4.58%. The average age of the documents analyzed was 18 years, with an average of 21.88 citations and an average of 4.58 authors. The United States, the United Kingdom, and Japan ranked first to third in terms of number of publications. Still, the United States, China, and Sweden were in a better position in terms of impact on the research network. Co-occurrence word analysis showed that significant attention was given to topics such as chronic inflammation in autism, acute inflammation in otitis media, and increased fluid in the middle ear. This study highlights the need to prioritize and focus attention on otitis, particularly otitis media, due to its prevalence and impact on public health. The use of scientometric software, such as Biblioshiny and CiteSpace, provides a valuable means of assessing research trends and identifying important areas for future study in the field of knowledge.

Prevalence of prolonged otitis media with effusion among 2 to 3 years old Cameroonian children in the era of 13-valent pneumococcal conjugate vaccines

Objectives

There is data scarcity on the overall effects of pneumococcal conjugate vaccines (PCVs) on otitis media (OM) in low- and middle-income countries. The impact of the 13-valent PCV (PCV13) program on OM was evaluated in Cameroon where infant vaccination was implemented in July 2011 using a 3-dose primary series at 6, 10 and 14 weeks of age.

Methods

Through community-based surveillance, we used a retrospective cohort study design to assess OM prevalence among PCV13-vaccinated children aged 24 to 36 months in 2015. This was compared with a 2013 age-matched cohort of PCV13-unvaccinated children. OM was diagnosed by clinical inspection for chronic suppurative OM (CSOM) and tympanometry for OM with effusion (OME). CSOM was defined as draining of the middle ear with duration of more than 2 weeks and prolonged OME was defined as a flat 'type B' tympanogram. PCV13-vaccinated and PCV13-unvaccinated cohorts were compared by calculating prevalence odds ratios for OM and baseline characteristics.

Results

Altogether, 111 OM cases were identified; 42/433 (9.7%) in the PCV13-unvaccinated in 2013 and 69/413 (16.7%) in the PCV13-vaccinated cohort in 2015. In the 2013 baseline survey, 3/433 (0.7%) children were identified with unilateral CSOM compared to 9/413 (2.2%) in the PCV13-vaccinated cohort in 2015. Bilateral prolonged OME was diagnosed in 7/433 (1.6%) PCV13-unvaccinated children and in 12/413 (2.9%) in PCV13-vaccinated children. Proportions of children with unilateral prolonged OME were 31/433 (7.2%) in the PCV13-unvaccinated group compared with 48/413 (11.6%) in the PCV13-vaccinated group. Multivariate logistic regression analysis showed evidence that PCV13-vaccinated children in 2015 had 40% less risk of contracting OM compared to PCV13-unvaccinated children in 2013 (adjusted prevalence odds ratios = 0.60 [95% confidence interval: 0.38 to 0.94], P = 0.025). Additionally, attributable proportion estimates show that, 58% of OM infections among the PCV13-vaccinated group would still have occurred despite PCV13 vaccination.

Conclusion

Our findings provide significant evidence on the effect of PCV13 in decreasing OM or OME among children in this age group. It also supports justification for government's continuation of PCV13 immunization program in the absence of GAVI's funding. Further research is needed to assess the long-term impact of the PCV13 program on in OM Cameroon.

Efficacy of Pneumococcal Vaccine on Otitis Media: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the effect of the pneumococcal vaccine (PCV) toward the surgical management and complications of otitis media.

DATA SOURCES

MEDLINE, EMBASE, PubMed, Scopus, and clinicaltrial.gov.

REVIEW METHODS

A systematic search was performed using a combination of keywords and standardized terms about PCV and surgical management or complications of otitis media. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies were screened by 3 independent reviewers. Risk of bias assessment, followed by meta-analysis in only randomized-controlled trials was conducted. Vaccine efficacy (VE) and 95% confidence interval (CI) were reported.

RESULTS

Of the 2649 abstracts reviewed, 27 studies were included in the qualitative analysis and were categorized into 6 outcomes: tympanostomy tube insertion, otitis media with effusion (OME), mastoiditis, spontaneous tympanic membrane (TM) perforation, recurrent acute otitis media (AOM), and severe AOM. Fifteen studies were included in the meta-analysis to evaluate the rate of tympanostomy tube insertion, OME, and recurrent AOM. PCV was significantly more effective in lowering the rate of tympanostomy tube insertion (VE, 22.2%; 95% CI, 14.6-29.8) and recurrent AOM (VE, 10.06%; 95% CI, 7.46-12.65) when compared with the control group, with no significant difference in reducing the incidence of OME. The qualitative analysis revealed that PCV had efficacy in preventing severe AOM and spontaneous TM perforation but the effect on mastoiditis remained unclear.

CONCLUSION

The PCV was effective in reducing the rate of tympanostomy tube insertion and the incidence of recurrent AOM with a nonsignificant effect in preventing OME in children.

20‑Valent Pneumococcal Conjugate Vaccine: Pediatric First Approval

20‑valent pneumococcal conjugate vaccine (PCV20; Prevnar 20®; Apexxnar®) is a pneumococcal conjugate vaccine (PCV) developed by Pfizer for active immunization for the prevention of pneumococcal infections. PCV20 has a similar structure and formulation to Pfizer's 13-valent PCV (PCV13; Prevnar 13®; Prevenar 13®), with the addition of polysaccharides to target seven further Streptococcus pneumoniae serotypes (8, 10A, 11A, 12F, 15B, 22F and 33F). PCV20 has been approved for active immunization for the prevention of pneumonia and invasive disease caused by S. pneumoniae in adults since June 2021 in the USA and since February 2022 in the EU. Following further evaluation of its safety, immunogenicity, and effectiveness in pediatric populations, in April 2023 PCV20 received its first pediatric approval, in the USA, for active immunization for the prevention of invasive pneumococcal disease (IPD) caused by S. pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F in individuals 6 weeks to 17 years of age and for the prevention of otitis media caused by S. pneumoniae serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F in individuals 6 weeks to 5 years of age. This article summarizes the milestones in the development of PCV20 leading to this first pediatric approval for active immunization for the prevention of IPD and otitis media caused by S. pneumoniae.

Evaluation of structural modification induced activation of pneumococcal polysaccharide by GC-MS for the conjugate vaccine

Polysaccharide (Ps) activation evaluation is an imperative quality attribute in a conjugate vaccine. Pneumococcal polysaccharide (PnPs) serotypes 5, 6B, 14, 19A and 23F were cyanylated for 3 and 8 min. The cyanylated and non-cyanylated polysaccharides were methanolysed and derivatized to assess the activation of each sugar by GC-MS. The activation of 22 and 27% serotype 6B and 11 and 36% in serotype 23 F Ps at 3 and 8 min respectively showed controlled conjugation kinetics with CRM197 carrier protein estimated by SEC-HPLC and optimal absolute molar mass by SEC-MALS. The Glc and Gal are the most commonly activated sugars of all PnPs serotypes while N-acetyl sugars PneuNAc, GalNAc and Rha in serotypes 5, 14 and 19A respectively showed >50% activation which contributes to conjugate aggregate formation at 8 min compared to 3 min cyanylation. The GC-MS analysis of structural modifications at functional groups entails important information to characterize the activated polysaccharide for consistent conjugate vaccine manufacturing.

Bridging the immunogenicity of a tetravalent dengue vaccine (TAK-003) from children and adolescents to adults

Immunobridging is an important methodology that can be used to extrapolate vaccine efficacy estimates to populations not evaluated in clinical studies, and that has been successfully used in developing many vaccines. Dengue, caused by a mosquito-transmitted flavivirus endemic to many tropical and subtropical regions, is traditionally thought of as a pediatric disease but is now a global threat to both children and adults. We bridged immunogenicity data from a phase 3 efficacy study of a tetravalent dengue vaccine (TAK-003), performed in children and adolescents living in endemic areas, with an immunogenicity study in adults in non-endemic areas. Neutralizing antibody responses were comparable in both studies following receipt of a two-dose TAK-003 schedule (months 0 and 3). Similar immune responses were observed across exploratory assessments of additional humoral responses. These data support the potential for clinical efficacy of TAK-003 in adults.

Public health impact and cost-effectiveness of 15-valent pneumococcal conjugate vaccine use among the pediatric population of the United States

BACKGROUND

Although use of the 13-valent pneumococcal conjugate vaccine (PCV13) among children has reduced incidence of pneumococcal disease, a considerable burden of disease remains. PCV15 is a new vaccine that contains pneumococcal serotypes 22F and 33F in addition to serotypes contained in PCV13. To inform deliberations by the Advisory Committee on Immunization Practices on recommendations for PCV15 use among U.S. children, we estimated the health impact and cost-effectiveness of replacing PCV13 with PCV15 within the routine infant immunization program in the United States. We also assessed the impact and cost-effectiveness of a supplementary PCV15 dose among children aged 2-5 years who have already received a full PCV13 series.

METHODS

We estimated the incremental number of pneumococcal disease events and deaths averted, costs per quality adjusted life-year (QALY) gained, and costs per life-year gained under different vaccination strategies using a probabilistic model following a single birth cohort of 3.9 million individuals (based on 2020 U.S. birth cohort). We assumed that vaccine effectiveness (VE) of PCV15 against the two additional serotypes was the same as the VE of PCV13. The cost of PCV15 use among children was informed from costs of PCV15 use among adults and from discussions with the manufacturer.

RESULTS

Our base case results found that replacing PCV13 with PCV15 prevented 92,290 additional pneumococcal disease events and 22 associated deaths, while also saving $147 million in costs. A supplementary PCV15 dose among children aged 2-5 years who were fully vaccinated with PCV13 prevented further pneumococcal disease events and associated deaths but at a cost of more than $2.5 million per QALY gained.

CONCLUSIONS

A further decrease in pneumococcal disease in conjunction with considerable societal cost savings could be expected from replacing PCV13 with PCV15 within the routine infant immunization program in the United States.

Cost-Effectiveness Analysis of Routine Use of 15-Valent Pneumococcal Conjugate Vaccine in the US Pediatric Population

This study evaluated the clinical and economic impact of routine pediatric vaccination with the 15-valent pneumococcal conjugate vaccine (PCV15, V114) compared with the 13-valent PCV (PCV13) from a societal perspective in the United States (US). A Markov decision-analytic model was constructed to estimate the outcomes for the entire US population over a 100-year time horizon. The model estimated the impact of V114 versus PCV13 on pneumococcal disease (PD) incidence, post meningitis sequalae, and deaths, taking herd immunity effects into account. V114 effectiveness was extrapolated from the observed PCV13 data and PCV7 clinical trials. Costs (2021$) included vaccine acquisition and administration costs, direct medical costs for PD treatment, direct non-medical costs, and indirect costs, and were discounted at 3% per year. In the base case, V114 prevented 185,711 additional invasive pneumococcal disease, 987,727 all-cause pneumonia, and 11.2 million pneumococcal acute otitis media cases, compared with PCV13. This led to expected gains of 90,026 life years and 96,056 quality-adjusted life years with a total saving of $10.8 billion. Sensitivity analysis showed consistent results over plausible values of key model inputs and assumptions. The findings suggest that V114 is a cost-saving option compared to PCV13 in the routine pediatric vaccination program.

Cost-effectiveness analysis of pediatric immunization program with 15-valent pneumococcal conjugate vaccine in Japan

BACKGROUND

The 15-valent pneumococcal conjugate vaccine (PCV15 or V114) has recently been approved for pediatric vaccination against pneumococcal diseases (PDs) in Japan. The study aims to evaluate the cost-effectiveness of pediatric vaccination with V114 versus 13-valent PCV (PCV13) in Japan.

METHODS

The study used a decision analytical Markov model to estimate the cost and effectiveness outcomes for a birth cohort in Japan over a 10-year time horizon. The model tracked the occurrences of acute PD events, including invasive PD (IPD), non-bacteremic pneumococcal pneumonia (NBPP) and pneumococcal acute otitis media (AOM) and the long-term impact of post-meningitis sequalae. Vaccine effectiveness was estimated based on literature and assumptions, and accounted for indirect effects and vaccine waning. The base case took the societal perspective, including both direct and indirect costs, while a healthcare payer perspective was modeled in a scenario analysis. Additional scenario analyses and sensitivity analyses were conducted.

RESULTS

In the base case, V114 was associated with an incremental gain of 24 quality-adjusted life years and a reduction of ¥365,610,955 in total costs compared to PCV13. It was expected to reduce the number of pneumococcal AOM, NBPP, and IPD cases by 1,832, 1,333 and 25, respectively. All scenario analyses and most sensitivity analyses showed that V114 was a dominant strategy compared to PCV13.

CONCLUSIONS

Pediatric vaccination with V114 is expected to lead to cost savings and more health benefits compared to PCV13 in Japan from both societal and healthcare payer perspectives. The findings are robust under plausible assumptions and inputs.

Estimating national, regional and provincial cost-effectiveness of introducing childhood 13-valent pneumococcal conjugate vaccination in China: a modelling analysis

Background

Although 13-valent pneumococcal conjugate vaccine (PCV13) is available in China's private market, it has yet to be introduced into the National Immunization Programme (NIP) and is therefore not available to large parts of the population. This study aimed to estimate the cost-effectiveness of including PCV13 in China's NIP at national and provincial levels.

Methods

We adopted a decision-tree Markov model to estimate the cost-effectiveness of adding 3-dose PCV13 in the NIP compared to the status quo in the private market from a societal perspective. The model hypothesized a birth cohort for five years after vaccine introduction. Treatment costs and vaccine program costs were calculated from Chinese Center for Disease Control and Prevention (CDC) and national insurance databases. Disease burden data, incidence rate ratios, and other parameters were derived from published and grey literature. Cases and deaths averted, quality-adjusted life years (QALYs) gained, and incremental cost-effectiveness ratios (ICERs) were estimated at the provincial, regional, and national levels. One-way, scenario and probabilistic sensitivity analyses were conducted to explore model uncertainty.

Findings

At the national level, introducing PCV13 in the NIP was predicted to prevent approximately 4807 pneumococcal deaths (66% reduction) and 1,057,650 pneumococcal cases (17% reduction) in the first five years of the 2019 birth cohort. Under the assumed base case price of US$ 25 per dose in the NIP, PCV13 in the NIP was cost-effective nationally with ICER of US$ 5.222 per QALY gained, and was cost-effective in 17 and cost-saving in 4 of the 31 provinces compared to the status quo. One-way and scenario sensitivity analyses indicated robust results when varying all model parameters, and probabilistic sensitivity analysis showed a 98% probability of cost-effectiveness nationally.

Interpretation

Our findings highlight the cost-effectiveness of introducing PCV13 in China's NIP. Provincial results supported subnational introduction of PCV13, and priority should be given to less socioeconomically developed provinces. Since vaccination cost is the most influential model parameter, efforts to improve PCV affordability after pooled procurement will benefit public health in a cost-effective manner.

Funding

The Bill & Melinda Gates Foundation.

Pathogenesis of Streptococcus pneumoniae serotype 3 during natural colonization and infections among children and its IgG correlate of protection in a mouse model

Current licensed pneumococcal conjugate vaccines (PCVs) are effective against pneumococcal diseases caused by the serotypes contained in the PCvs However; several studies evaluating pneumococcal colonization and acute otitis-media (AOM) prevention in young children vaccinated with PCV13, observed less effectiveness against serotype-3. One possible reason for less effectiveness may be release of the capsular polysaccharide (CPS) of serotype-3 (CPS-3) as an immune evasion mechanism. Here we evaluated free CPS-3 levels released from 6 clinical isolates from young children compared to WU2 strain and to serotype-19A CPS (CPS-19A) released in vitro when interacting with nasopharyngeal, middle-ear and lung cell-lines. Clinical serotype-3 strains showed greater release of CPS than WU2 with the interaction to 2 cell-lines and all 6 clinical serotype-19A strains. We next evaluated CPS-3 vs CPS-19A levels in middle-ear fluid (MEF) and the nasopharynx (NP) of young children and found higher levels of CPS-3 compared to CPS-19A in MEF during AOM but not in NP secretions during colonization. With anti-CPS-3 IgG in MEF and NP secretions at time of health and onset of AOM, a significant negative correlation (r = -0.75, p < 0.05) between unbound anti-CPS-3 IgG levels and free- anti-CPS-3 in MEF were found, and a significant lower detection of unbound anti-CPS-3 IgG in NP at the time of health with serotype-3 SPN (p < 0.05) compared to irrelevant SPN serotypes were found. In a mouse model of AOM and pneumonia, we sought a correlate of protection against serotype-3 infection using human serum-derived anti-CPS-3 IgG. We conclude that serotype-3 clinical isolates from children release more capsule than WU2 strains or 19A strains during in vitro testing; release more capsule in the MEF of children during AOM than serotype 19A; unbound anti-CPS-3 IgG levels negatively correlate with free-anti-CPS-3; and a level of 2.8 µg/ml anti-CPS-3 antibody protects mice from AOM and pneumonia but not colonization.

Effect of pneumococcal conjugate vaccine on prevalence of otitis media with effusion among children in Vietnam

PURPOSE

Otitis media with effusion (OME) is common in young children and is associated with Streptococcus pneumoniae infection. We aimed to determine the impact of pneumococcal conjugate vaccine (PCV) introduction on the prevalence of OME and OME associated with vaccine-type (VT) or non-VT.

METHODS

Population-based cross-sectional surveys were conducted in pre- (2016) and post-PCV periods (2017, 2018, and 2019) at selected communes in Nha Trang, Vietnam. For each survey, we randomly selected 60 children aged 4-11 months and 60 aged 14-23 months from each commune. Nasopharyngeal sample collection and tympanic membrane examination by digital otoscope were performed. S. pneumoniae was detected and serotyped by lytA qPCR and microarray. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated using Firth's logistic regression, stratified by age group.

RESULTS

Over the four surveys, 2089 children had a bilateral ear examination. Compared to pre-PCV, the prevalence of OME reduced in 2018 (OR 0.51, 95 %CI 0.28-0.93) and in 2019 (OR 0.53, 95 %CI 0.29-0.97) among the <12-month-olds, but no significant reduction among the 12-23-month-olds. The prevalence of OME associated with VT pneumococcus decreased in 2018 and 2019 (2018: OR 0.14, 95 %CI 0.03-0.55; 2019: OR 0.20, 95 %CI 0.05-0.69 in the <12-months-olds, 2018: OR 0.05, 95 %CI 0.00-0.44, 2019: OR 0.41, 95 %CI 0.10-1.61 in the 12-23-months-olds). The prevalence of OME associated with non-VT pneumococcus increased in the 12-23-month-olds in 2017 (OR 3.09, 95 %CI 1.47-7.45) and returned to the pre-PCV level of prevalence in 2018 and 2019 (OR 0.94, 95 %CI 0.40-2.43 and 1.40, 95 %CI 0.63-3.49).

CONCLUSION

PCV10 introduction was associated with a reduction of OME prevalence in infants but not in older children.

Etiology, Diagnosis, Complications, and Management of Acute Otitis Media in Children

Acute otitis media (AOM) is the most common infectious disease encountered by children under the age of two years and the most common cause of antibiotic use in children in the United States. AOM causes irritability, sleeplessness, decreased appetite, imbalance, and dizziness in patients, especially young children. This assessment was conducted to measure the effectiveness of surgical interventions in treating AOM. We reviewed the present findings regarding the etiology, clinical presentations, diagnosis, treatment, and surgical treatment of complications of AOM. Pain associated with AOM (otalgia) can be severe enough to cause parents to seek treatment for their infants or children. Various suggested measures have been used to treat AOM; antibiotic treatment with amoxicillin is still the treatment of choice for AOM, yet other antibiotics may be used in cases of allergy to penicillin or recent use of amoxicillin. Surgical intervention has been introduced and studied as a diagnostic, therapeutic, and preventive measure for AOM; nevertheless, a few studies have shown that surgical interventions are beneficial in treating and preventing AOM compared to the common practice of using antibiotics. Overdiagnosis of AOM is widespread, leading to injudicious antibiotic use, which contributes to antibiotic resistance. Further management should be determined together with the parent, particularly if observation is the primary intervention.

A cost-effectiveness analysis of PHiD-CV compared to PCV13 in a national immunization program setting in Tunisia

Background

In response to the substantial clinical and economic burden of diseases caused by Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) in Tunisia, the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) was recently introduced into the national immunization program. However, there has yet to be a full-scale health economic analysis comparing currently available pneumococcal conjugate vaccines (PCVs) in Tunisia.

Methods

A Markov model that simulated the disease processes of invasive pneumococcal disease (IPD), pneumonia, and acute otitis media (AOM) over a newborn cohort lifetime was used to evaluate the cost-effectiveness/utility of PHiD-CV and the 13-valent pneumococcal conjugate vaccine (PCV13) from payer’s perspective, using 3% discounting. Vaccine effects were considered for up to 9 years of age.

Results

Vaccination with PHiD-CV or PCV13 was estimated to avert approximately 700 cases of IPD (200 meningitis, 500 bacteremia), and around 5,000 cases of all-cause pneumonia. However, PHiD-CV vaccination was estimated to avert around 4,000 additional AOM cases (18,000) versus PCV13 (14,000). Both PCVs were demonstrated to be cost-effective interventions, but PHiD-CV was estimated to generate additional cost savings of almost $1 million US dollars (USD) with similar levels of clinical benefits. An additional scenario which incorporated serotype-specific vaccine efficacy found no significant change in overall results.

Conclusion

PCVs are a cost-effective strategy to relieve the burden associated with diseases caused by S.pneumoniae and NTHi in Tunisia. PHiD-CV is more cost-effective than PCV13, generating similar health benefits, at a reduced net cost of almost $1 million USD per vaccinated cohort.

Non-diphtheriae Corynebacterium species are associated with decreased risk of pneumococcal colonization during infancy

Streptococcus pneumoniae (pneumococcus) is a leading cause of severe infections among children and adults. Interactions between commensal microbes in the upper respiratory tract and S. pneumoniae are poorly described. In this study, we sought to identify interspecies interactions that modify the risk of S. pneumoniae colonization during infancy and to describe development of the upper respiratory microbiome during infancy in a sub-Saharan African setting. We collected nasopharyngeal swabs monthly (0-6 months of age) or bimonthly (6-12 months of age) from 179 mother-infant dyads in Botswana. We used 16S ribosomal RNA gene sequencing to characterize the nasopharyngeal microbiome and identified S. pneumoniae colonization using a species-specific PCR assay. We detect S. pneumoniae colonization in 144 (80%) infants at a median age of 71 days and identify a strong negative association between the relative abundance of the bacterial genera Corynebacterium within the infant nasopharyngeal microbiome and the risk of S. pneumoniae colonization. Using in vitro cultivation experiments, we demonstrate growth inhibition of S. pneumoniae by secreted factors from strains of several Corynebacterium species isolated from these infants. Finally, we demonstrate that antibiotic exposures and the winter season are associated with a decline in the relative abundance of Corynebacterium within the nasopharyngeal microbiome, while breastfeeding is associated with an increase in the Corynebacterium relative abundance. Our findings provide novel insights into the interspecies interactions that contribute to colonization resistance to S. pneumoniae and suggest that the nasopharyngeal microbiome may be a previously unrecognized mechanism by which environmental factors influence the risk of pneumococcal infections during childhood. Moreover, this work lays the foundation for future studies seeking to use targeted manipulation of the nasopharyngeal microbiome to prevent infections caused by S. pneumoniae.

The broader impacts of otitis media and sequelae for informing economic evaluations of pneumococcal conjugate vaccines

INTRODUCTION

Otitis media (OM) is a common childhood infection. Pneumococcal conjugate vaccines (PCVs) prevent OM episodes, thereby reducing short- and long-term clinical, economic, humanistic, and societal consequences. Most economic evaluations of PCVs focus on direct health gains and cost savings from prevented acute episodes but do not fully account for the broader societal impacts of OM prevention.

AREAS COVERED

This review explores the broader burden of OM on children, caregivers, and society to better inform future economic evaluations of PCVs.

EXPERT OPINION

OM causes a substantial burden to society through long-term sequelae, productivity losses, reduced quality of life for children and caregivers, and contribution to antimicrobial resistance from inappropriate antibiotic use. The effect of PCVs on acute OM has been recognized globally, yet the broader impact has not been consistently quantified, studied, or communicated. Economic evaluations of PCVs must evolve to include broader effects for patients, caregivers, and society from OM prevention. Future PCVs with broader coverage may further reduce OM incidence and antimicrobial resistance, but optimal uptake will depend on increasing the recognition and use of novel frameworks that include broader benefits. Communicating the full value of PCVs to decision makers may result in wider access and positive societal returns.

Systematic review of the efficacy, effectiveness and impact of high-valency pneumococcal conjugate vaccines on otitis media

Otitis media (OM) is a common disease of childhood and available pneumococcal conjugate vaccines (PCVs), with different compositions, could have different impact on OM reduction. This systematic literature review evaluated available data describing the efficacy, effectiveness, and impact of 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) and 13-valent PCV (PCV13) on OM outcomes. Statistically significant reductions in all-cause and complicated OM, tympanostomy tube placement and OM-related hospitalizations were consistently observed after the introduction of PHiD-CV and PCV13. Impact studies with data in children <2 years of age using PCV13 report 47–51% and PHiD-CV 34–43% reduction of all-cause OM (primary care, outpatient, ambulatory, emergency department visits) compared to periods before PCV introduction. When the impact of both vaccines is assessed in comparable settings, some studies suggest PHiD-CV may offer better protection against some OM outcomes. Well-designed, head-to-head comparisons are needed to better understand the differences and guide vaccination policies.

What is the context?

Pneumococcal vaccines are highly effective in preventing pneumonia and meningitis in children. The two main pneumococcal vaccines are PHiD-CV (Synflorix, GSK) and PCV13 (Prevenar 13, Pfizer). Both vaccines have been shown to provide protection against otitis media despite differing in their composition.

However, it is currently unknown if both vaccines confer similar level of protection against otitis media.

What is new?

We conducted a literature review to evaluate the effects of PHiD-CV and PCV13 on otitis media.

From 33 articles, we found that:

‡Both vaccines were effective in reducing doctor visits for otitis media as well as the number of severe cases and cases requiring hospitalization.

‡Four studies suggested a higher level of protection provided by PHiD-CV compared to PCV13, although more data is needed to confirm this finding.

What is the impact?

Available information shows that PHiD-CV and PCV13 are effective in preventing a proportion of otitis media during childhood.

Given the remaining substantial burden associated with the disease and the related significant usage of antibiotics, the development of improved vaccines with higher impact on otitis media would be welcome.

Transition of Serotype 35B Pneumococci From Commensal to Prevalent Virulent Strain in Children

In our community-based prospective cohort study in young children, we observed a significant increase in pneumococcal serotype 35B nasopharyngeal (NP) commensal colonization during the 2011–2014 timeframe, but these strains were not associated with disease. Beginning in 2015 and continuing through to the present, the serotype 35B virulence changed, and it became the dominant bacteria isolated and associated with pneumococcal acute otitis-media (AOM) in our cohort. We performed comparative analyses of 250 35B isolates obtained from 140 children collected between 2006 and 2019. Changes in prevalence, clonal-complex composition, and antibiotic resistance were analyzed. Seventy-two (29%) of 35B isolates underwent whole-genome sequencing to investigate genomic changes associated with the shift in virulence that resulted in increased rates of 35B-associated AOM disease. 35B strains that were commensals and AOM disease-causing were mainly associated with sequence type (ST) 558. Antibiotic concentrations of β-lactams and ofloxacin necessary to inhibit growth of 35B strains rose significantly (2006–2019) (p<0.005). However, only isolates from the 35B/ST558 showed significant increases in MIC₅₀ of penicillin and ofloxacin between the years 2006–2014 and 2015–2019 (p=0.007 and p<0.0001). One hundred thirty-eight SNPs located in 34 different genes were significantly associated with post-2015 strains. SNPs were found in nrdG (metal binding, 10%); metP and metN (ABC transporter, 9%); corA (Mg²⁺ transporter, 6%); priA (DNA replication, 5%); and on the enzymic gene ldcB (LD-carboxypeptidase, 3%). Pneumococcal serotype 35B strains was a common NP commensal during 2010–2014. In 2015, a shift in increasing number of AOM cases occurred in young children caused by 35B, that was associated with changes in genetic composition and antibiotic susceptibility.

Pneumococcal conjugate vaccines in Taiwan: optimizing health gains in children and older adults through constrained optimization modeling: Pneumococcal conjugate vaccines optimization in Taiwan

OBJECTIVES

Budgetary constraints force healthcare authorities to set priorities for optimal vaccine interventions. A comprehensive decision-making tool would help inform the best combination and sequence of introduction of vaccines within constrained budgets.

METHODS

Looking at available vaccines against pneumococcal infections in Taiwan (10/13-valent pneumococcal conjugate vaccines [PCV10, PCV13] and 23-valent pneumococcal polysaccharide vaccine [PPV23]), a constrained optimization (CO) model was used to assess the optimal combination of vaccines in children and older adults that would maximize the quality-adjusted life years under predefined budget constraints. Scenario analyses were carried out to evaluate the impact of vaccine efficacy (VE) on the optimized solution.

RESULTS

The CO model demonstrated that the optimal sequence of vaccine introduction was PPV23 in older adults and PCV10 in children. The optimal solution was mostly driven by the potential to reduce disease burden in the older adult population. The VE of PPV23 in older adults and the VE of PCV vaccines against serotype 19A invasive pneumococcal disease had little impact on the optimal solution.

CONCLUSIONS

The CO approach can be used to set priorities for introducing new vaccines while maximizing health gains per age group within the constrained National Vaccine Fund for the prevention of pneumococcal disease in Taiwan.

Effect of Erdosteine on Middle Ear Effusion in Rats by Mediating TLR4 Signaling Pathway

The study aimed to investigate the effect of erdosteine on middle ear effusion in rats through mediating the Toll-like receptor 4 (TLR4) signaling pathway. Rats were injected with endotoxin to prepare the model of acute secretory otitis media (SOM). Then, they were divided into an acute SOM model group (model group, n = 15) and erdosteine treatment group (18 mg/kg, gavage, treatment group, n = 15). Besides, a normal group (n = 15) was set up. Two weeks later, routine biochemical indicators such as aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were detected. The inflammatory effusion due to otitis media was scored. The content of myeloperoxidase (MPO), matrix metalloproteinase (MMP), and tumor necrosis factor-beta (TNF-β) in middle ear lavage fluid was detected via enzyme-linked immunosorbent assay (ELISA). Additionally, histomorphological changes were observed with the help of hematoxylin-eosin (HE) staining, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assays were carried out to measure the expression levels of TLR4 pathway genes and proteins as well as the messenger ribonucleic acid (mRNA) expression levels of key factors for otitis media (mucin 2 (MUC2) and MUC5A). In the model group, the levels of AST, ALP, and glutamic-pyruvic transaminase (GPT) were significantly increased (p < 0.05). Besides, the content of MPO, MMP, and TNF-β was overtly raised in the model group (p < 0.05), while it was notably lowered in the treatment group (p < 0.05). In the treatment group, the cilia were slightly swollen, and inflammatory cells were fewer. The mRNA levels of MUC2, MUC5A, and pathway genes TLR4 and c-Jun N-terminal kinase (JNK) were elevated in the model group. In addition, the protein assay results revealed that the protein levels of TLR4 and JNK were evidently increased in the model group. Erdosteine can treat the middle ear effusion in rats by repressing the activation of the TLR4 signaling pathway.

Particular matter influences the incidence of acute otitis media in children

Particulate matter (PM) is the main component of air pollution. Children are vulnerable to PM and acute otitis media (AOM), which is one of the most common diseases in children. However, studies on the relationship between AOM in children and PM are rare and their results are inconsistent. The aim of this study is to investigate the effect of PM on AOM in children on the basis of the Korea National Health Insurance service (NHIS) claims data. NHIS claim data from 2008 to 2015 was used to identify outpatient visits, antibiotic use to treat AOM, and demographic data. This data was combined with the data on PM_2.5 (≤ 2.5 μm) and PM₁₀ (≤ 10 μm according to its aerodynamic diameter) level extracted from air pollution data from Korean National Institute of Environmental Research for 16 administrative regions. The children with AOM were divided into three age groups (< 2, 2–4, 5–10 years). Generalized linear Poisson regression model was used to estimate the association between AOM and PM using daily counts of AOM and daily mean PM concentrations. It was adjusted to temperature, wind, humidity, season, year, age, and region. With an increase in PM_2.5 of 10 μg/m³, the relative risk of OM increased by 4.5% in children under 2 years of age. The effect of PM_2.5 was strongest influence on the day of exposure. The exposure to PM₁₀ was related to the incidence of AOM on the day of exposure and the following seven days in all three age groups. The PM concentrations did not strongly affect either AOM duration or the use of antibiotics to cure AOM. The RR in the each lag day after exposure to PM₁₀ was diverse according to the age groups. Regardless of PM size and children’s age, the PM levels are positively related to the incidence of AOM. Both PM_2.5 and PM₁₀ have the most adverse effects on children under 2 years of age and on the day of exposure.

Association of pneumococcal serotype with susceptibility to antimicrobial drugs: a systematic review and meta-analysis

BACKGROUND

Pneumococcal serotypes differ in antimicrobial susceptibility. However, patterns and causes of this variation are not comprehensively understood.

METHODS

We undertook a systematic review of epidemiologic studies of pneumococci isolated from carriage or invasive disease among children globally from 2000-2019. We evaluated associations of each serotype with nonsusceptibility to penicillin, macrolides, and trimethoprim/sulfamethoxazole. We evaluated differences in the prevalence of nonsusceptibility to major antibiotic classes across serotypes using random effects meta-regression models, and assessed changes in prevalence of nonsusceptibility after implementation of pneumococcal conjugate vaccines (PCVs). We also evaluated associations between biological characteristics of serotypes and their likelihood of nonsusceptibility to each drug.

RESULTS

We included data from 129 studies representing 32,187 isolates across 52 countries. Within serotypes, the proportion of nonsusceptible isolates varied geographically and over time, in settings using and those not using PCVs. Factors predicting enhanced fitness of serotypes in colonization as well as enhanced pathogenicity were each associated with higher likelihood of nonsusceptibility to penicillin, macrolides, and trimethoprim/sulfamethoxazole. Increases in prevalence of nonsusceptibility following PCV implementation were evident among non-PCV serotypes including 6A, 6C, 15A, 15B/C, 19A, and 35B; however, this pattern was not universally evident among non-PCV serotypes. Post-vaccination increases in nonsusceptibility for serotypes 6A and 19A were attenuated in settings that implemented PCV13.

CONCLUSIONS

In pneumococci, nonsusceptibility to penicillin, macrolides, and trimethoprim/sulfamethoxazole is associated with more frequent opportunities for antibiotic exposure during both prolonged carriage episodes and when serotypes cause disease. These findings suggest multiple pathways leading to resistance selection in pneumococci.

Nasopharyngeal Carriage in Children After the Introduction of Generalized Infant Pneumococcal Conjugate Vaccine Immunization in Germany

Epidemiological data on nasopharyngeal (NP) bacterial carriage in children in Germany are scarce. We prospectively characterized NP colonization to evaluate the impact of pneumococcal immunization. We longitudinally collected NP swabs from 2-month-old infants (visit 1; V1) at eight representative pediatric offices 10/2008-06/2009. The second swabs were taken at age 9–12 months (V2); the third swab was taken 3–6 months after the booster vaccination at age 17–19 months (V3), and the fourth swab (V4) at age 59–61 months. Samples were broth enriched, cultured for bacteria, and isolates were serotyped. Demographic risk factors for colonization were evaluated. Among 242 vaccinees, bacterial NP carriage increased with age [from 27.2% (V1) to 70.1% (V4)]; leading isolates were S. pneumoniae, H. influenzae, M. catarrhalis, and S. pyogenes. Overall pneumococcal carriage increased [14.7% (V1), 31.5% (V2), 34.8% (V3), 42.2% (V4)], being even greater among day-care attendees. Serotype distribution changed during the study period, with vaccine serotypes declining. At visit 4, 10-valent pneumococcal conjugate vaccine (PCV10) serotypes were no longer among the NP flora, while some serotypes unique to 13-valent pneumococcal conjugate vaccine (PCV13; 3 and 19A) were found. In Germany, universal infant PCV immunization was associated with an almost complete eradication of PCV-serotypes and concomitant increase of non-PCV-serotypes, mainly 11A, 22F, and 23A.

Downward Trend in Resident Myringotomy and Tympanostomy Tube Experience

INTRODUCTION/OBJECTIVE

Historically, myringotomy, and the insertion of tympanostomy tubes has served as one of the initial surgical training experiences for residents. Resident experience with this procedure since the introduction of pneumococcal conjugate vaccines has not been well described in the literature. The objective of this study was to identify trends in resident training experience with chronic otitis media-related surgeries, such as myringotomy and tympanostomy tube placement. While multiple factors influence resident experience, we hypothesize that resident experience has decreased since the introduction of the pneumococcal 13-valent conjugate vaccine (PCV13).

METHODS AND MATERIALS

In a retrospective review of Accreditation Council for Graduate Medical Education (ACGME) National Data Reports, mean number of myringotomy and tympanostomy tube cases logged in the Resident Case Log System from 2006 to 2019 were collated and plotted against years to identify monotonic trends. Mann-Whitney U test was used to compare pre-PCV13 era and post-PCV13 era data.

RESULTS

Since the introduction of PCV13, there is a national decreasing trend in the myringotomy and tympanostomy tube placement by otolaryngology residents (P = .001).

CONCLUSIONS

Otologic surgeries are an important part of resident education and historically have served as one of the initial surgical training experiences for residents. There has been a significant reduction in the number of myringotomy and tympanostomy procedures performed by otolaryngology residents in the past decade. While multiple factors influence resident experience, it is possible that introduction of PCV13 has impacted resident exposure to myringotomy and tympanostomy tube placement. Resident proficiency with this procedure has likely not been affected by introduction of PCV13. Data should be reassessed in 5 years to determine if an impact of the PCV13 vaccine on resident training is evident.

Vaccine-Preventable Disease Incidence Based on Clinically, Radiologically and Etiologically Confirmed Outcomes: Systematic Literature Review and Re-analysis of Pneumococcal Conjugate Vaccine Efficacy Trials

Background

Vaccine regulatory decision making is based on vaccine efficacy against etiologically confirmed outcomes, which may underestimate the preventable disease burden. To quantify this underestimation, we compared vaccine-preventable disease incidence (VPDI) of clinically defined outcomes with radiologically/etiologically confirmed outcomes.

Methods

We performed a systematic review of efficacy trials for several vaccines (1997–2019) and report results for pneumococcal conjugate vaccines. Data were extracted for outcomes within a clinical syndrome, organized from most sensitive to most specific. VPDI was determined for each outcome, and VPDI ratios were calculated, with a clinically defined outcome (numerator) and a radiologically/etiologically confirmed outcome (denominator).

Results

Among 9 studies, we calculated 27 VPDI ratios; 24 had a value >1. Among children, VPDI ratios for clinically defined versus vaccine serotype otitis media were 0.6 (95% CI not calculable), 2.1 (1.5–3.0), and 3.7 (1.0–10.2); the VPDI ratios comparing clinically defined with radiologically confirmed pneumonia ranged from not calculable to 2.7 (1.2–10.4); the VPDI ratio comparing clinically suspected invasive pneumococcal disease (IPD) with laboratory-confirmed IPD was 3.8 (95% CI not calculable). Among adults, the ratio comparing clinically defined with radiologically confirmed pneumonia was 1.9 (−6.0 to 9.1) and with vaccine serotype–confirmed pneumonia was 2.9 (.5–7.8).

Conclusions

While there is substantial uncertainty around individual point estimates, there is a consistent trend in VPDI ratios, most commonly showing under-ascertainment of 1.5- to 4-fold, indicating that use of clinically defined outcomes is likely to provide a more accurate estimate of a pneumococcal conjugate vaccine’s public health value.

The mucosal immune system of the upper respiratory tract and recent progress in mucosal vaccines

The mucosal immune system prevents microorganism invasion through mucosal surfaces and consists of inductive and effector sites. Nasopharynx-associated lymphoid tissue (NALT) functions as an inductive site, inducing mucosal immune responses in the upper respiratory tract. It follows that intranasal vaccines may prevent upper respiratory infections. To induce and enhance the immune response by administering inactivated antigens intranasally, mucosal adjuvants have been developed, including mutant cholera toxin and cationic cholesteryl pullulan nanogel, which do not accumulate in the central nervous system. Moreover, multivalent pneumococcal polysaccharide conjugate vaccines are used to prevent invasive pneumococcal infections and otitis media, although they only provide moderate protection against acute otitis media because non-vaccine serotypes of Streptococcus pneumoniae and Haemophilus influenzae also cause this infection. To address this problem, pneumococcal surface protein A of S. pneumoniae and P6 of H. influenzae are used as broad-spectrum vaccine antigens. Alternatively, phosphorylcholine (PC) is present in the cell walls of both gram-positive and gram-negative bacteria and induces immune responses through antigenic activity. The significant effects of PC as a mucosal vaccine have been demonstrated through intranasal and sublingual immunization in mice. Furthermore, intranasal administration of PC reverses increases in IgE levels and prevents allergic rhinitis. After immunization with pneumococcal polysaccharide conjugate vaccine, intranasal immunization with PC boosts immune responses to vaccine strains and to PC itself. Thus, PC may be useful as a mucosal vaccine to prevent upper respiratory infections and allergic rhinitis, and it could be used as a booster to the currently used pneumococcal vaccine as it protects against non-vaccine strains.

Serum antibody levels to pneumococcal polysaccharides 22F, 33F, 19A and 6A that correlate with protection from colonization and acute otitis media in children

BACKGROUND

Serotypes 22F and 33F have been added to a new pneumococcal-conjugate vaccine (PCV-15) because of their prevalence in causing invasive pneumococcal diseases (IPD).

METHOD

We measured anti-polysaccharide 22F, 33F, 19A and 6A antibodies in children before and after pneumococcal colonization and acute otitis media (AOM) episodes caused by these specific-serotypes. A two-step method for construction of correlate of protection (COP) models included using a generalized estimating equation for the relationship between antibody level, age and colonization history followed by logistic-regression modelling that included colonization or AOM episodes as independent variables, and age adjusted antibody level as the predictor.

RESULTS

A vaccine-induced serum antibody level of 0.45 μg/ml for 22F, 0.51 μg/ml for 6A and 4.1 μg/ml for 19A correlated with prevention of pneumococcal colonization by respective serotypes (insufficient number of cases for 33F to find COP against colonization). Antibody levels of 0.25 μg/ml for 22F, 33F and 6A and 2 μg/ml for 19A correlated with prevention of AOM by the respective serotypes.

CONCLUSIONS

A COP threshold of anti-22F, 33F, 19A and 6A serum antibodies for NP colonization and AOM in young children can be derived using GEE and logistic regression modelling.

Bacterial Spectrum of Spontaneously Ruptured Otitis Media in a 7-Year, Longitudinal, Multicenter, Epidemiological Cross-Sectional Study in Germany

We analyzed middle ear fluid (MEF) and nasopharyngeal swabs (NPS) from spontaneously ruptured acute otitis media (AOM) cases occurring in children under 5 years in Germany. The aim of the study was the assessment of disease burden and bacterial etiology in the era of routine pneumococcal vaccination. Furthermore, we aimed to compare isolates from MEF with isolates from NPS and to analyze the Streptococcus pneumoniae serotype distribution. We analyzed MEF and NPS samples in children 2 months to 5 years for vaccination status, frequency of bacterial strains, serotype/emm-type distribution of S. pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes; and intraindividual correlation between MEF and NPS. From 2008 to 2014, MEF samples were collected from 2,138 subjects of which 2,001 (93.6%) also provided an NPS sample. In 851 of 2,138 MEF samples (39.8%), we identified organisms with confirmed pathogenic potential—S. pyogenes: 315 (14.7%), S. pneumoniae: 170 (8.0%), Staphylococcus aureus: 168 (7.9%), H. influenzae: 133 (6.2%), and Moraxella catarrhalis. Among NPS samples, 1,018 (50.9%) contained S. pneumoniae, 775 (38.7%) H. influenzae, 648 (32.4%) M. catarrhalis, and 344 (17.2%) S. pyogenes. Over the seven study years, the number of AOM patients steadily decreased, while the recruiting base remained constant. S. pneumoniae MEF isolates decreased by 86%, with serotype 3 being the most prevalent (25.7–42.9%). PCV13-non-PCV7-non-3 serotypes reduced to 0%. Among NPS, PCV7 serotypes decreased from 14.1 to 3.7%, PCV10: 17.6 to 3.7%, and PCV13: 55.3 to 25.7%. PCV13-non-PCV7-non-3 serotypes increased in the first 3 years of the study (17.1–22.9%), then decreased to 4.6% in year 7. Non-typeable H. influenzae reduced from 87.1 to 41.7% in MEF and from 91.4 to 54.2% in NPS. MEF and NPS isolates from the same subject were identical for 91.9% of S. pneumoniae, 99.0% of S. pyogenes, and 83.3% of H. influenzae. Among PCV7-vaccinated children, 5.6% had a PCV7 vaccine type in the MEF sample, and among PCV13-vaccinated children, 51.7% had a PCV13 serotype. Among non-vaccinated children, the percentages were 14.8 and 70.4. Pneumococcal conjugate vaccination has impacted the prevalence and etiology of spontaneously ruptured otitis media among children in Germany. Overall case numbers and pneumococcal vaccine type cases have strongly decreased.

Association of nasopharyngeal viruses and pathogenic bacteria in children and their parents with and without HIV

BACKGROUND

Bacteria and respiratory viruses co-occur in the nasopharynx, and their interactions may impact pathogenesis of invasive disease. Associations of viruses and bacteria in the nasopharynx may be affected by HIV.

METHODS

We conducted a nested case-control study from a larger cohort study of banked nasopharyngeal swabs from families with and without HIV in West Bengal India, to look at the association of viruses and bacteria in the nasopharynx of parents and children when they are asymptomatic. Quantitative polymerase chain reaction for 4 bacteria and 21 respiratory viruses was run on 92 random nasopharyngeal swabs from children--49 from children living with HIV (CLH) and 43 from HIV uninfected children (HUC)-- and 77 swabs from their parents (44 parents of CLH and 33 parents of HUC).

RESULTS

Bacteria was found in 67% of children, viruses in 45%, and both in 27% of child samples. Staphylococcus aureus (53%) was the most common bacteria, followed by Streptococcus pneumoniae (pneumococcus) (37%) in children and parents (53, 20%). Regardless of HIV status, viruses were detected in higher numbers (44%) in children than their parents (30%) (p = 0.049), particularly rhinovirus (p = 0.02). Human rhinovirus was the most frequently found virus in both CLH and HUC. Children with adenovirus were at six times increased risk of also having pneumococcus (Odds ratio OR 6, 95% CI 1.12-31.9) regardless of HIV status. In addition, the presence of rhinovirus in children was associated with increased pneumococcal density (Regression coeff 4.5, 1.14-7.9). In CLH the presence of rhinovirus increased the risk of pneumococcal colonization by nearly sixteen times (OR 15.6, 1.66-146.4), and, pneumococcus and S. aureus dual colonization by nearly nine times (OR 8.7).

CONCLUSIONS

Children more frequently carried viruses regardless of HIV status. In CLH the presence of rhinovirus, the most frequently detected virus, significantly increased co-colonization with pneumococcus and S. aureus.

Statistical inference in matched case-control studies of recurrent events

BACKGROUND

The concurrent sampling design was developed for case-control studies of recurrent events. It involves matching for time. Standard conditional logistic-regression (CLR) analysis ignores the dependence among recurrent events. Existing methods for clustered observations for CLR do not fit the complex data structure arising from the concurrent sampling design.

METHODS

We propose to break the matches, apply unconditional logistic regression with adjustment for time in quintiles and residual time within each quintile, and use a robust standard error for observations clustered within persons. We conducted extensive simulation to evaluate this approach and compared it with methods based on CLR. We analysed data from a study of childhood pneumonia to illustrate the methods.

RESULTS

The proposed method and CLR methods gave very similar point estimates of association and showed little bias. The proposed method produced confidence intervals that achieved the target level of coverage probability, whereas the CLR methods did not, except when disease incidence was low.

CONCLUSIONS

The proposed method is suitable for the analysis of case-control studies with recurrent events.

[Therapeutic approach to acute otitis media in primary care in an urban area. Delayed antibiotic prescription evaluation]

BACKGROUND AND OBJECTIVES

Acute otitis media (AOM) is one of the most frequent causes of consultation and antibiotic prescription in pediatrics. The objective of this work is to evaluate the practice of delayed antibiotic prescription in AOM in pediatrics primary care.

MATERIAL AND METHODS

Observational, retrospective study, through reviewing of medical records in a primary care center of Aragon Community of children with OMA in which doctors perform delayed prescription. Logistic regression analyzes possibly related to antibiotic prescription factors.

RESULTS

1,390 episodes of AOM are analyzed in 696 patients. Immediate antibiotic prescription is performed in 67.6% (95% CI 65.1-70.0) of episodes, exclusive symptomatic in 13.7% (95% CI 11.9-15.6), and delayed antibiotic in 18.7% (95% CI 16.7-20.8), finally being given in 53.5% (95% CI 47.4-59.5) of these. Factors significantly related to final antimicrobial dispensation in delayed prescription are aged between 0 and 2 years (OR 1.89, 95% CI 1.25-2.87), bilaterality (OR 2.54, 95% CI 1.48-4.35), ear pain (OR 0.49, 95% CI 0.29-0.82), fever (OR 2.67, 95% CI 1.95-3.65), bulging (OR 3.63, 95% CI 2.50-5.29) and otorrhea (OR 25.98, 95% CI 12.75-52.92). The same factors have influence on global prescription of antibiotics. Amoxicillin (74.6%) is the most indicated antibiotic, followed by amoxicillin-clavulanic (17.0%).

CONCLUSIONS

Delayed prescription in AOM seems to be useful to reduce antibiotics consumption, being necessary to advance in its implantation.

Effectiveness of the 7- and 13-Valent Pneumococcal Conjugate Vaccines Against Vaccine-Serotype Otitis Media

Background

Despite the demonstrated impact of pneumococcal vaccine (PCV) implementation on otitis media (OM), demonstration of real-life serotype-specific effectiveness of the 7-valent and 13-valent PCVs (PCV7 and PCV13) is lacking owing to the paucity of culture-positive cases. Furthermore, prelicensure PCV13 efficacy against OM was not studied.

Methods

The study was conducted from October 2009 to July 2013. Case patients were children aged 5–35 months with OM (mostly complex OM [recurrent/nonresponsive, spontaneously draining, chronic with effusion]) from whom middle-ear fluid culture was obtained; controls were contemporary children with rotavirus-negative gastroenteritis in a prospective population-based rotavirus surveillance, from the same age group with similar ethnic distribution and geographic location. Vaccine effectiveness (VE) was estimated as 1 minus the odds ratio using unconditional logistic regression, adjusting for time since PCV implementation, age, and ethnicity.

Results

A total of 223 case patients and 1370 controls were studied. Serotypes 19F and 19A together caused 56.1% of all vaccine-type (VT) OM. VE of ≥2 PCV doses in children aged 5–35 months was demonstrated as follows: PCV7 against OM due to PCV7 serotypes, 57.2% (95% confidence interval, 6.0%–80.5%); PCV13 against OM due to PCV13 serotypes, 77.4% (53.3%–92.1%); PCV13 against OM due to the 6 additional non-PCV7 serotypes 67.4% (17.6%–87.1%); PCV13 against OM due to serotype 19F, 91.3% (1.4%–99.2%); and PCV13 against OM due to serotype 3, 85.2% (23.9%–98.4%). PCV7 and PCV13 VE against OM due to serotype 19A in children aged 12–35 months was 72.4% (95% confidence interval, 6.2%–91.9%) and 94.6% (33.9%–99.6%), respectively.

Conclusions

PCV7 and PCV13 were effective against complex OM caused by the targeted serotypes.

Streptococcus pneumoniae Serotypes Carried by Young Children and Their Association With Acute Otitis Media During the Period 2016-2019

Background: Streptococcus pneumoniae (Sp) is a major cause of acute otitis media (AOM). Pneumococcal conjugate vaccine (PCV) programs have altered pneumococcal serotype epidemiology in disease and carriage. In this study, we used samples collected during a cross-sectional study to examine if the clinical picture of acute otitis media (AOM) in young children exposed to the PCV program in Belgium was related to the carried pneumococcal strains, and if their carriage profile differed from healthy children attending daycare centers. Material/Methods: In three collection periods from February 2016 to May 2018, nasopharyngeal swabs and background characteristics were collected from children aged 6-30 months either presenting at their physician with AOM (AOM-group) or healthy and attending day care (DCC-group). Clinical signs of AOM episodes and treatment schedule were registered by the physicians. Sp was detected, quantified, and characterized using both conventional culture analysis and real-time PCR analysis. Results: Among 3,264 collected samples, overall pneumococcal carriage and density were found at similar rates in both AOM and DCC. As expected non-vaccine serotypes were most frequent: 23B (AOM: 12.3%; DCC: 17.4%), 11A (AOM: 7.5%; DCC: 7.4%) and 15B (AOM: 7.5%; DCC: 7.1%). Serotypes 3, 6C, 7B, 9N, 12F, 17F, and 29 were more often found in AOM than in DCC (p-value < 0.05), whereas 23A and 23B were less often present in AOM (p-value < 0.05). Antibiotic non-susceptibility of Sp strains was similar in both groups. No predictors of AOM severity were identified. Conclusion: In the present study, overall carriage prevalence and density of S. pneumoniae were found similar in young children with AOM and in healthy children attending day-care centers in Belgium. Certain serotypes not currently included in the PCV vaccines were found to be carried more often in children with AOM than in DCC, a finding that might suggest a relationship between these serotypes and AOM.

No evidence from a systematic review for the use of probiotics to prevent otitis media

AIM

This systematic review evaluates the current evidence for the use of probiotics in the prevention of acute otitis media (AOM) in children.

METHODS

This study is registered with PROSPERO prior to commencement. PubMed, MEDLINE, EMBASE and Cochrane database were searched using relating keywords. All literature was screened to determine relatability to the topic. Review articles were also screened for additional literature.

RESULTS

Thirteen studies were found on probiotics and their role in preventing AOM in children. They ranged in quality from poor to moderate. Half (2/4) of the studies that used nasal probiotic formulations showed a significant difference in reducing otitis media, while only a third (3/9) of the studies using oral formulations suggest benefit in reducing AOM. None of the studies demonstrated significant adverse effects from probiotics.

CONCLUSION

The evidence for any effect of probiotics on the prevention of AOM is limited, and the overall low quality of studies makes it difficult to draw definitive conclusions. No serious adverse events were noted, and there is some evidence to suggest possible benefit with nasal probiotic administration.

Pneumococcal conjugate vaccines for preventing acute otitis media in children

BACKGROUND

Prior to introducing pneumococcal conjugate vaccines (PCVs), Streptococcus pneumoniae was most commonly isolated from the middle ear fluid of children with acute otitis media (AOM). Reducing nasopharyngeal colonisation of this bacterium by PCVs may lead to a decline in AOM. The effects of PCVs deserve ongoing monitoring since studies from the post-PCV era report a shift in causative otopathogens towards non-vaccine serotypes and other bacteria. This updated Cochrane Review was first published in 2002 and updated in 2004, 2009, 2014, and 2019.

OBJECTIVES

To assess the effect of PCVs in preventing AOM in children up to 12 years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, Web of Science, and two trials registers, ClinicalTrials.gov and WHO ICTRP, to 11 June 2020.

SELECTION CRITERIA

Randomised controlled trials of PCV versus placebo or control vaccine.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. The primary outcomes were frequency of all-cause AOM and adverse effects. Secondary outcomes included frequency of pneumococcal AOM and frequency of recurrent AOM (defined as three or more AOM episodes in six months or four or more in one year). We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 15 publications of 11 trials (60,733 children, range 74 to 37,868 per trial) of 7- to 11-valent PCVs versus control vaccines (meningococcus type C vaccine in three trials, and hepatitis A or B vaccine in eight trials). We included one additional publication of a previously included trial for this 2020 update. We did not find any relevant trials with the newer 13-valent PCV. Most studies were funded by pharmaceutical companies. Overall, risk of bias was low. In seven trials (59,415 children), PCVs were administered in early infancy, whilst four trials (1318 children) included children aged one year and over who were either healthy or had a history of respiratory illness. There was considerable clinical heterogeneity across studies, therefore we reported results from individual studies. PCV administered in early infancy PCV7 The licenced 7-valent PCV with CRM197 as carrier protein (CRM197-PCV7) was associated with a 6% (95% confidence interval (CI) -4% to 16%; 1 trial; 1662 children) and 6% (95% CI 4% to 9%; 1 trial; 37,868 children) relative risk reduction (RRR) in low-risk infants (moderate-certainty evidence), but was not associated with a reduction in all-cause AOM in high-risk infants (RRR -5%, 95% CI -25% to 12%). PCV7 with the outer membrane protein complex of Neisseria meningitidis serogroup B as carrier protein (OMPC-PCV7) was not associated with a reduction in all-cause AOM (RRR -1%, 95% CI -12% to 10%; 1 trial; 1666 children; low-certainty evidence). CRM197-PCV7 and OMPC-PCV7 were associated with 20% (95% CI 7% to 31%) and 25% (95% CI 11% to 37%) RRR in pneumococcal AOM, respectively (2 trials; 3328 children; high-certainty evidence), and CRM197-PCV7 with 9% (95% CI -12% to 27%) and 10% (95% CI 7% to 13%) RRR in recurrent AOM (2 trials; 39,530 children; moderate-certainty evidence). PHiD-CV10/11 The effect of a licenced 10-valent PCV conjugated to protein D, a surface lipoprotein of Haemophilus influenzae, (PHiD-CV10) on all-cause AOM in healthy infants varied from 6% (95% CI -6% to 17%; 1 trial; 5095 children) to 15% (95% CI -1% to 28%; 1 trial; 7359 children) RRR (low-certainty evidence). PHiD-CV11 was associated with 34% (95% CI 21% to 44%) RRR in all-cause AOM (1 trial; 4968 children; moderate-certainty evidence). PHiD-CV10 and PHiD-CV11 were associated with 53% (95% CI 16% to 74%) and 52% (95% CI 37% to 63%) RRR in pneumococcal AOM (2 trials; 12,327 children; high-certainty evidence), and PHiD-CV11 with 56% (95% CI -2% to 80%) RRR in recurrent AOM (1 trial; 4968 children; low-certainty evidence). PCV administered at a later age PCV7 We found no evidence of a beneficial effect on all-cause AOM of administering CRM197-PCV7 in children aged 1 to 7 years with a history of respiratory illness or frequent AOM (2 trials; 457 children; moderate-certainty evidence) and CRM197-PCV7 combined with a trivalent influenza vaccine in children aged 18 to 72 months with a history of respiratory tract infections (1 trial; 597 children; moderate-certainty evidence). CRM197-PCV9 In 1 trial including 264 healthy daycare attendees aged 1 to 3 years, CRM197-PCV9 was associated with 17% (95% CI -2% to 33%) RRR in parent-reported all-cause otitis media (very low-certainty evidence). Adverse events Nine trials reported on adverse effects (77,389 children; high-certainty evidence). Mild local reactions and fever were common in both groups, and occurred more frequently in PCV than in control vaccine groups: redness (< 2.5 cm): 5% to 20% versus 0% to 16%; swelling (< 2.5 cm): 5% to 12% versus 0% to 8%; and fever (< 39 °C): 15% to 44% versus 8% to 25%. More severe redness (> 2.5 cm), swelling (> 2.5 cm), and fever (> 39 °C) occurred less frequently (0% to 0.9%, 0.1% to 1.3%, and 0.4% to 2.5%, respectively) in children receiving PCV, and did not differ significantly between PCV and control vaccine groups. Pain or tenderness, or both, was reported more frequently in PCV than in control vaccine groups: 3% to 38% versus 0% to 8%. Serious adverse events judged to be causally related to vaccination were rare and did not differ significantly between groups, and no fatal serious adverse event judged causally related to vaccination was reported.

AUTHORS' CONCLUSIONS

Administration of the licenced CRM197-PCV7 and PHiD-CV10 during early infancy is associated with large relative risk reductions in pneumococcal AOM. However, the effects of these vaccines on all-cause AOM is far more uncertain based on low- to moderate-certainty evidence. We found no evidence of a beneficial effect on all-cause AOM of administering PCVs in high-risk infants, after early infancy, and in older children with a history of respiratory illness. Compared to control vaccines, PCVs were associated with an increase in mild local reactions (redness, swelling), fever, and pain and/or tenderness. There was no evidence of a difference in more severe local reactions, fever, or serious adverse events judged to be causally related to vaccination.

In vitro Inhibition of Clinical Isolates of Otitis Media Pathogens by the Probiotic Streptococcus salivarius BLIS K12

Otitis media is a common childhood infection, frequently requiring antibiotics. With high rates of antibiotic prescribing and increasing antibiotic resistance, new strategies in otitis media prevention and treatment are needed. The aim of this study was to assess the in vitro inhibitory activity Streptococcus salivarius BLIS K12 against otitis media pathogens. Efficacy of the bacteriocin activity of S. salivarius BLIS K12 against the otitis media isolates was assessed using the deferred antagonism test. Overall, 48% of pathogenic isolates exhibited some growth inhibition by S. salivarius BLIS K12. S. salivarius BLIS K12 can inhibit the in vitro growth of the most common pathogens.

Expanding the role of bacterial vaccines into life-course vaccination strategies and prevention of antimicrobial-resistant infections

A crisis in bacterial infections looms as ageing populations, increasing rates of bacteraemia and healthcare-associated infections converge with increasing antimicrobial resistance and a paucity of new antimicrobial classes. New initiatives are needed to develop bacterial vaccines for older adults in whom immune senescence plays a critical role. Novel vaccines require an expanded repertoire to prevent mucosal diseases such as pneumonia, skin and soft tissue infections and urinary tract infections that are major causes of morbidity and mortality in the elderly, and key drivers of antimicrobial resistance. This review considers the challenges inherent to the prevention of bacterial diseases, particularly mucosal infections caused by major priority bacterial pathogens against which current vaccines are sub-optimal. It has become clear that prevention of many lung, urinary tract and skin infections requires more than circulating antibodies. Induction of Th1/Th17 cellular responses with tissue-resident memory (Trm) cells homing to mucosal tissues may be a pre-requisite for success.

Cost-effectiveness evaluation of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine for children in Taiwan

Background

Streptococcus pneumoniae (S. pneumoniae) and non-typeable Haemophilus influenzae (NTHi) are substantial contributors to morbidity and mortality of diseases including invasive pneumococcal diseases (IPDs), pneumonia and acute otitis media (AOM) worldwide. In Taiwan, 10-valent pneumococcal polysaccharide and NTHi protein D conjugate vaccine (PHiD-CV) and 13-valent pneumococcal conjugate vaccine (PCV13) are licensed in children against pneumococcal disease. In addition to S. pneumoniae, clinical trials suggest efficacy of PHiD-CV against NTHi AOM. This study aims at evaluating the cost-effectiveness of a 2 + 1 schedule of PHiD-CV vs. PCV13 2 + 1 in the universal mass vaccination program of infants in Taiwan.

Methods

A published Markov cohort model was adapted to simulate the epidemiological burden of IPD, pneumonia and AOM for a birth cohort in Taiwan over 10 years. The probability of entering a specific health state was based on the incidence rate of the diseases. Only direct medical costs were included, and costs and outcomes were discounted annually. Vaccine efficacy assumptions were based on published data and validated by a panel of independent experts. Clinical, epidemiological, and serotype distribution data were based on locally published data or the National Health Insurance Research Database. Price parity of vaccines was assumed. Published pneumococcal disease-related disutility weights were used due to lack of local data. Incremental cost-effectiveness ratio was calculated and benchmarked against the recommended threshold in Taiwan. Extensive one-way sensitivity analysis, alternative scenarios and probabilistic sensitivity analysis were performed to test the robustness of the results.

Results

PHiD-CV would potentially reduce the number of NTHi-related AOM cases substantially and prevent comparable IPD and pneumonia-related cases and deaths compared to PCV13. Over a 10-year horizon, PHiD-CV is estimated to dominate PCV13, saving 6.7 million New Taiwan Dollars (NTD) and saving 21 quality-adjusted life years. The result was robust over a wide range of sensitivity analyses. The dominance of PHiD-CV was demonstrated in 90.5% of the simulations.

Conclusions

PHiD-CV 2 + 1 would provide comparable prevention of IPD, pneumonia cases and additional reduction of NTHi-AOM cases, and is considered dominant compared with PCV13 2 + 1 in Taiwan.

Clinical practice guidelines for the diagnosis and management of acute otitis media in children-2018 update

OBJECTIVE

"Clinical Practice Guidelines for the Diagnosis and Management of Acute Otitis Media in Children-2018 update (2018 Guidelines)" aim to provide appropriate recommendations about the diagnosis and management of children with acute otitis media (AOM), including recurrent acute otitis media (recurrent AOM), in children under 15 years of age. These evidence-based recommendations were created with the consensus of the subcommittee members, taking into consideration unique characteristics of bacteriology and antimicrobial susceptibilities of AOM pathogens in Japan, as well as global advances in vaccines.

METHODS

The subcommittee re-evaluated key clinical issues based on SCOPE (a master plan of the guidelines) and created clinical questions (CQ) about the diagnosis and management of AOM patients. A literature search of the publications from 2013 to 2016 were added to the Guidelines 2013, not only to assess the evidence on the effectiveness of vaccines, but also to provide up to date information of the bacteriology and antimicrobial susceptibilities of AOM causative pathogens in Japan.

RESULTS

We have proposed guidelines for disease severity-based management of AOM patients, after classifying AOM severity into mild, moderate, and severe, based on age, clinical manifestations, and otoscopic findings.

CONCLUSIONS

Precise otoscopic findings are essential for judging AOM severity, which can lead to appropriate management of AOM patients.

Comparison of pneumococcal conjugate vaccine (PCV-13) cellular immune responses after primary and booster doses of vaccine

Since their widespread use, pneumococcal conjugate vaccines (PCVs) have proven effective at reducing both invasive and noninvasive pneumococcal diseases and nasopharyngeal carriage of Streptococcus pneumoniae (Spn). To establish this level of protection, a three-dose schedule with a single booster (3 + 1) was the immunization regime in the USA. Alternatively, WHO-approved schedules of 3 + 0 and 2 + 1 are now becoming adopted in many countries to reduce the cost of vaccination. Sustained protection from pneumococcal disease and carriage requires persisting levels of antibody and cellular immune memory. Although antibody responses to PCVs are well studied, less is known concerning the cellular response to the vaccine in young children. In this report, circulating PCV-13 serotype-specific B and T cell memory in paired blood samples from children before and after PCV13 dose 3 and booster immunizations was analyzed to determine changes in the adaptive immune response. No significant differences in memory B cell populations were detected comparing post dose 2 vs. post dose 3. However, the booster dose significantly increased the frequency of Spn-specific memory B cells compared to the pre-booster. Spn-specific memory T cells were not detected with the method used. These data suggest that booster vaccination increases Spn-specific memory B cells that may impact long-term protective antibody titers.

Comparison of anti-capsular antibody quantity and functionality in children after different primary dose and booster schedules of 13 valent-pneumococcal conjugate vaccine

Different schedules for pediatric use of the 13-valent pneumococcal conjugate vaccine (PCV-13) are recommended in different countries and the U.S. Advisory Committee on Immunization Practices (ACIP) has considered potential of changing from 3 primary doses plus a booster (3p + 1) to two primary doses plus a booster (2p + 1) for protection against Streptococcus pneumoniae. In this paper, we report results of IgG antibody measured by ELISA and opsonophagocytic assay (OPA) after 2p, 3p, at child age 15 months of pre-booster and 18 months (post-booster) in serum samples opportunistically available from a prior study that focused on PCV effectiveness against AOM. A total of ~ 100 sera for each of the 4 study time points (390 sera tested) from 169 children were tested. Geometric mean concentrations (GMCs) and percentage of children exceeding the presumed protective antibody thresholds measured by ELISA and OPA were calculated. 2p doses produced lower antibody levels measured by ELISA but not OPA until the booster dose for serotypes 6A, 6B, 5 and 23F only. Booster dosing at 15 months resulted in significant increases in antibody. There was no difference in the percentage of children with ≥ correlate of protection (COP) for OPA for 2p vs 3p doses except for serotype 23F. A 2p + 0 or 3p + 0 schedule would likely result in many children failing to sustain protective levels of antibody into the second year of life. We conclude that protection from invasive pneumococcal infection in early childhood would be similar for most serotypes in PCV13 using a 2p + 1 or 3p + 1 but not a 2p + 0 or 3p + 0 schedule.

Childhood vaccines and antibiotic use in low- and middle-income countries

Vaccines may reduce the burden of antimicrobial resistance, in part by preventing infections for which treatment often includes the use of antibiotics1-4. However, the effects of vaccination on antibiotic consumption remain poorly understood-especially in low- and middle-income countries (LMICs), where the burden of antimicrobial resistance is greatest5. Here we show that vaccines that have recently been implemented in the World Health Organization's Expanded Programme on Immunization reduce antibiotic consumption substantially among children under five years of age in LMICs. By analysing data from large-scale studies of households, we estimate that pneumococcal conjugate vaccines and live attenuated rotavirus vaccines confer 19.7% (95% confidence interval, 3.4-43.4%) and 11.4% (4.0-18.6%) protection against antibiotic-treated episodes of acute respiratory infection and diarrhoea, respectively, in age groups that experience the greatest disease burden attributable to the vaccine-targeted pathogens6,7. Under current coverage levels, pneumococcal and rotavirus vaccines prevent 23.8 million and 13.6 million episodes of antibiotic-treated illness, respectively, among children under five years of age in LMICs each year. Direct protection resulting from the achievement of universal coverage targets for these vaccines could prevent an additional 40.0 million episodes of antibiotic-treated illness. This evidence supports the prioritization of vaccines within the global strategy to combat antimicrobial resistance8.

Sensitive quantitation of low level free polysaccharide in conjugate vaccines by size exclusion chromatography-reverse phase liquid chromatography with UV detection

The level of free polysaccharide is a critical quality attribute of polysaccharide-protein conjugate vaccines. The work presented describes a simple and sensitive method for the determination of low level free polysaccharides in multiple polysaccharide-protein conjugates. The method utilizes a reverse phase (RP) column to perform a size exclusion chromatography (SEC) separation of free polysaccharide and a reverse phase liquid chromatography (RPLC) separation of free protein and protein-polysaccharide conjugate. The use of phosphate buffer in the mobile phase enables the universal and sensitive detection of low level free polysaccharides at UV 200 nm. The method has been validated to monitor low level free polysaccharide (<1 %) in multiple polysaccharide-protein conjugates. The limit of quantitation is 2 μg/ml or 0.3 % free polysaccharide in 0.6 mg/ml polysaccharide-protein conjugate. The accuracy is in the range of 94.1.0-108.5 %.

Pneumococcal Vaccines

Streptococcus pneumoniae is a Gram-Positive pathogen that is a major causative agent of pneumonia, otitis media, sepsis and meningitis across the world. The World Health Organization estimates that globally over 500,000 children are killed each year by this pathogen. Vaccines offer the best protection against S. pneumoniae infections. The current polysaccharide conjugate vaccines have been very effective in reducing rates of invasive pneumococcal disease caused by vaccine type strains. However, the effectiveness of these vaccines have been somewhat diminished by the increasing numbers of cases of invasive disease caused by non-vaccine type strains, a phenomenon known as serotype replacement. Since, there are currently at least 98 known serotypes of S. pneumoniae, it may become cumbersome and expensive to add many additional serotypes to the current 13-valent vaccine, to circumvent the effect of serotype replacement. Hence, alternative serotype independent strategies, such as vaccination with highly cross-reactive pneumococcal protein antigens, should continue to be investigated to address this problem. This chapter provides a comprehensive discussion of pneumococcal vaccines past and present, protein antigens that are currently under investigation as vaccine candidates, and other alternatives, such as the pneumococcal whole cell vaccine, that may be successful in reducing current rates of disease caused by S. pneumoniae.

Efficacy, safety and immunogenicity of a pneumococcal protein-based vaccine co-administered with 13-valent pneumococcal conjugate vaccine against acute otitis media in young children: A phase IIb randomized study

BACKGROUND

Native American populations experience a substantial burden of pneumococcal disease despite use of highly effective pneumococcal conjugate vaccines (PCVs). Protein-based pneumococcal vaccines may extend protection beyond the serotype-specific protection elicited by PCVs.

METHODS

In this phase IIb, double-blind, controlled trial, 6-12 weeks-old Native American infants randomized 1:1, received either a protein-based pneumococcal vaccine (dPly/PhtD) containing pneumolysin toxoid (dPly, 10 µg) and pneumococcal histidine triad protein D (PhtD, 10 µg) or placebo, administered along with 13-valent PCV (PCV13) at ages 2, 4, 6 and 12-15 months. Other pediatric vaccines were given per the routine immunization schedule. We assessed vaccine efficacy (VE) against acute otitis media (AOM) and acute lower respiratory tract infection (ALRI) endpoints. Immunogenicity, reactogenicity and unsolicited adverse events were assessed in a sub-cohort and serious adverse events were assessed in all children.

RESULTS

1803 infants were randomized (900 dPly/PhtD; 903 Control). VE against all episodes of American Academy of Pediatrics (AAP)-defined AOM was 3.8% (95% confidence interval: -11.4, 16.9). Point estimates of VE against other AOM outcomes ranged between 2.9% (-9.5, 14.0) and 5.2% (-8.0, 16.8). Point estimates of VE against ALRI outcomes ranged between -4.4% (-39.2, 21.8) and 2.0% (-18.3, 18.8). Point estimates of VE tended to be higher against first than all episodes but the confidence intervals included zero. dPly/PhtD vaccine was immunogenic and had an acceptable reactogenicity and safety profile after primary and booster vaccination in Native American infants.

CONCLUSIONS

The dPly/PhtD vaccine was immunogenic and well tolerated, however, incremental efficacy in preventing AAP-AOM over PCV13 was not demonstrated.

CLINICAL TRIALS REGISTRATION

NCT01545375 (www.clinicaltrials.gov).

Impact of the 13-valent pneumococcal conjugate vaccine on the incidences of acute otitis media, recurrent otitis media and tympanostomy tube insertion in children after its implementation into the national immunization program in Turkey

The aim of this study was to investigate changes in the incidences of acute otitis media (AOM), recurrent AOM (rAOM) and tympanostomy tube (TT) insertion in children following the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the national immunization program (NIP) of Turkey in April 2011. National coverage for the PCV7 was 97% in 2009, 93% in 2010, 96% in 2011 and for the PVC13 was 97% in 2012, 97% in 2013, 96% in 2014, 97% in 2015, 98% in 2016, and 96% in 2017 for Turkish children younger than 12 months of age. A total of 499932 pediatric visits were recorded, and AOM was diagnosed in 23005 (4.6%) children. The incidence of AOM in children ≤5 years of age decreased from 10700/100000 (2011) to 4712/100000 (2017), with a significant decreasing trend (p < .001, r = -0.965). When the mean annual incidences of AOM between the transition period of PCV13 (years 2011/2012) were compared with those of a post-PCV13 period (years 2016/2017) for children ≤5 years of age, the incidence of AOM was found to be decreased by 54% (p = 0.013). The mean incidence of TT insertion was found to be decreased by 65% (p = 0.003) between the transition period of PCV13 and a post-PCV13 period for children ≤5 years of age. On the other hand, rAOM incidence was found to be increased in whole pediatric age groups. Our study showed a significant decrease in the incidences of AOM and TT insertion in children ≤5 years old after implementation of PCV13 in the NIP in Turkey.

Prevention of hospital-acquired pneumonia

PURPOSE OF REVIEW

Hospital-acquired pneumonia (HAP) is the leading cause of death from hospital-acquired infection. Little work has been done on strategies for prevention of HAP. This review aims to describe potential HAP prevention strategies and the evidence supporting them. Oral care and aspiration precautions may attenuate some risk for HAP. Oral and digestive decontamination with antibiotics may be effective but could increase risk for resistant organisms. Other preventive measures, including isolation practices, remain theoretical or experimental.

RECENT FINDINGS

Hospital-acquired pneumonia occurs because of pharyngeal colonization with pathogenic organisms and subsequent aspiration of these pathogens.

SUMMARY

Most potential HAP prevention strategies remain unproven.