Burden of disease caused by Haemophilus influenzae type b in children younger than 5 years: global estimates

T cell independent antibody responses with class switch and memory using peptides anchored on liposomes

Vaccines generally require T lymphocytes for B-cell activation and immunoglobulin class switching in response to peptide or protein antigens. In the absence of T cells, limited IgG class switch takes place, germinal centers are short-lived, and the B cells lack memory. Here, immunization of mice with liposomes containing 15mer peptides and monophosphoryl lipid A (MPLA) as adjuvant, induced T-cell independent (TI) IgG class switch within three days, as well as germinal center formation. The antibody responses were long-lived, strictly dependent on Toll-like receptor 4 (TLR4) signaling, partly dependent on Bruton's tyrosine kinase (BTK) signal transmission, and independent of signaling through T-cell receptors, MHC class II and inflammasome. The antibody response showed characteristics of both TI type 1 and TI type 2. All IgG subclasses could be boosted months after primary immunization, and the biological function of the secreted antibodies was demonstrated in murine models of allergic anaphylaxis and of bacterial infection. Moreover, antibody responses after immunization with peptide- and MPLA-loaded liposomes could be triggered in neonatal mice and in mice receiving immune-suppressants. This study demonstrates T-cell independent endogenous B-cell memory and recall responses in vivo using a peptide antigen. The stimulation of these antibody responses required a correct and dense assembly and administration of peptide and adjuvant on the surface of liposomes. In the future, TI vaccines may prove beneficial in pathological conditions in which T-cell immunity is compromised through disease or medicines or when rapid, antibody-mediated immune protection is needed.

Host-microbe interactions at the blood-brain barrier through the lens of induced pluripotent stem cell-derived brain-like endothelial cells

Microbe-induced meningoencephalitis/meningitis is a life-threatening infection of the central nervous system (CNS) that occurs when pathogens are able to cross the blood-brain barrier (BBB) and gain access to the CNS. The BBB consists of highly specialized brain endothelial cells that exhibit specific properties to allow tight regulation of CNS homeostasis and prevent pathogen crossing. However, during meningoencephalitis/meningitis, the BBB fails to protect the CNS. Modeling the BBB remains a challenge due to the specialized characteristics of these cells. In this review, we cover the induced pluripotent stem cell-derived, brain-like endothelial cell model during host-pathogen interaction, highlighting the strengths and recent work on various pathogens known to interact with the BBB. As stem cell technologies are becoming more prominent, the stem cell-derived, brain-like endothelial cell model has been able to reveal new insights in vitro, which remain challenging with other in vitro cell-based models consisting of primary human brain endothelial cells and immortalized human brain endothelial cell lines.

Comparative Genomic Analysis of Bacterial Data in BV-BRC: An Example Exploring Antimicrobial Resistance

As genomic and related data continue to expand, research biologists are often hampered by the computational hurdles required to analyze their data. The National Institute of Allergy and Infectious Diseases (NIAID) established the Bioinformatics Resource Centers (BRC) to assist researchers with their analysis of genome sequence and other omics-related data. Recently, the PAThosystems Resource Integration Center (PATRIC), the Influenza Research Database (IRD), and the Virus Pathogen Database and Analysis Resource (ViPR) BRCs merged to form the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) at https://www.bv-brc.org/ . The combined BV-BRC leverages the functionality of the original resources for bacterial and viral research communities with a unified data model, enhanced web-based visualization and analysis tools, and bioinformatics services. Here we demonstrate how antimicrobial resistance data can be analyzed in the new resource.

National Danish surveillance of invasive clinical Haemophilus influenzae isolates and their resistance profile

INTRODUCTION

This study aimed to investigate the epidemiology, serotype distribution, phenotypical antibiogram, and molecular resistance gene characteristics of invasive Haemophilus influenzae infections in Denmark from 2014 to 2022. Additionally, the potential impact of outdoor temperature and COVID-19 restrictions on the epidemiology of H. influenzae was assessed.

MATERIALS AND METHODS

Invasive H. influenzae isolates were received from patients with positive culture results from cerebrospinal fluid, blood, or other sterile sites. Sample data were obtained from the Danish laboratory surveillance system/MiBa database, and whole-genome sequencing (WGS) was performed on the isolates. The incidence rates and distribution of H. influenzae cases were analyzed, and antibiotic susceptibility were assessed.

RESULTS

A total of 1,007 invasive H. influenzae cases were identified, with serotyping conducted for 752 (74.7%) isolates. The median incidence per year of H. influenzae was 2.0 cases per 100,000, with the highest incidence in 2014 and the lowest in 2020. The majority of H. influenzae isolates were non-typeable H. influenzae (NTHi), while the most prominent serotypes were serotype f followed by serotype b. Bacteremia cases accounted for the majority (88.6%) of occurrences, although meningitis cases showed an increasing trend during the time period. The age group 85+ exhibited the highest incidence. The implementation of COVID-19 preventive interventions in 2020 resulted in a significant reduction in H. influenzae incidence, which returned to pre-COVID levels in 2021. A negative correlation was observed between monthly H. influenzae cases and outdoor temperature. An overall level of genetic beta-lactamase resistance of 26.3% was observed divided into 10.6% beta-lactamase-positive ampicillin-resistant (gBLPAR), 13.6% beta-lactamase-negative ampicillin-resistant (gBLNAR) and 2.1% beta-lactamase-positive amoxicillin clavulanate-resistant (gBLPACR). Other non-beta-lactam resistance traits were detected in 7.6% of isolates (primarily aminoglycoside-modifying enzymes).

CONCLUSION

The overall incidence of H. influenzae in Denmark returned to stable levels after the COVID-19 epidemic, with NTHi strains dominating. The COVID-19 preventive interventions led to a major reduction in incidence. A significant negative correlation between the incidence of H. influenzae and temperature was observed. The study revealed an overall genetic beta-lactam resistance rate of 26.3%, and the concordance between genotypic and phenotypic beta-lactam resistance was high (98.2%).

Factors associated with recommendation behaviors of four non-National Immunization Program vaccines: a cross-sectional survey among public health workers in China

BACKGROUND

Immunization is a crucial preventive measure to safeguard children under five years old against a range of diseases. In China, the coverage rate of non-National Immunization Program (non-NIP) vaccines can be improved by leveraging the recommendation from public health workers. Hence, understanding the influencing factors of recommendation behaviors assume paramount importance. This study aims to investigate influencing factors of public health workers' recommendation behaviors towards non-NIP vaccines, with a particular emphasis on financial incentives.

METHODS

A cross-sectional survey was conducted using a multi-stage sampling method in 2019 from August to October. 627 public health workers were recruited from 148 community healthcare centers in ten provincial-level administrative divisions in China. An anonymous questionnaire was used to collect demographic information, attitudes towards vaccination, and recommendation behaviors towards non-NIP vaccines, including Haemophilus influenzae type b (Hib) vaccine, pneumococcal conjugate vaccine, varicella vaccine, and rotavirus vaccine. Descriptive analysis and multivariate logistic regression analysis were adopted in this study.

RESULTS

Of the 610 public health workers with complete survey data, 53.8%, 57.4%, 84.1%, and 54.1% often recommended Hib vaccine, pneumococcal pneumonia vaccine (PCV), varicella vaccine, and rotavirus vaccine, respectively. Logistic regression revealed that gender (Hib vaccine: OR = 0.4, 95% CI: 0.2-0.8; PCV: OR = 0.4, 95% CI: 0.2-0.8; rotavirus vaccine: OR = 0.3, 95% CI: 0.2-0.6), financial incentives for non-NIP vaccination (Hib vaccine: OR = 1.9, 95% CI: 1.1-3.6; PCV: OR = 2.1, 95% CI: 1.1-3.9; rotavirus vaccine: OR = 2.0, 95% CI: 1.1-3.8) and perception of vaccine safety (Hib vaccine: OR = 2.7, 95% CI: 1.1-7.0; PCV: OR = 3.2, 95% CI: 1.2-8.0; rotavirus vaccine: OR = 3.0, 95% CI: 1.2-7.7) were associated with public health workers' recommendation towards Hib vaccine, PCV and rotavirus vaccine.

CONCLUSIONS

The findings highlighted public health workers' recommendation behaviors of non-NIP vaccines in China and revealed strong association between vaccine recommendation and financial incentives. This highlights the importance of financial incentives in public health workers' recommendation toward non-NIP vaccines in China. Proper incentives are recommended for public health workers to encourage effective health promotion in immunization practices.

Better adherence to childhood Haemophilus influenzae type b vaccination with combination vaccines compared to single-antigen vaccines: Evidence from China

Background

The coverage of Haemophilus influenzae type b (Hib) vaccination remains suboptimal in China, and this study aimed to investigate the influencing factors of caregivers' Hib-containing vaccine choices and the association between combination vaccine use and adherence to Hib immunisation schedule among Chinese children.

Methods

From August to October 2019, a cross-sectional survey was conducted in 148 community health care centres from ten provinces in China, which collected vaccination records from 5294 children aged 6-59 months. The children were categorised into three groups based on their Hib-containing vaccine receipt: unvaccinated group, monovalent vaccine group, and combination vaccine group. The outcome measures included: (1) receipt and choice of Hib-containing vaccines, and (2) completion of the three-dose schedule. Multinomial logistic regression was used to evaluate the influencing factors of Hib-containing vaccine receipt and choice, and logistic regression was adopted to investigate the associations between vaccine choice and schedule completion.

Results

Of the 5294 children, 19.53% received monovalent vaccines only, 22.59% received at least one dose of combination vaccines, and 57.88% were not vaccinated against Hib. The overall three-dose completion rate was 27.03%. The multinomial logistic (mlogit) regression findings indicated strong associations of socioeconomic status and Hib-containing vaccine supply with vaccination status. Multiple logistic regression among those who received at least one Hib-containing dose demonstrated a 3-fold increase in the likelihood of three-dose schedule completion by children who received any combination dose compared with those received single-antigen vaccines only (adjusted odds ratio (aOR) = 3.97 (95% CI = 3.14-5.03)).

Conclusions

Findings from the current study provide a more comprehensive understanding of the strong relationship between combination vaccine receipt and completion outcomes. Facing the suboptimal Hib vaccination rate in China, the use of combination vaccines could help increase vaccination compliance, and appropriate government actions to reduce out-of-pocket burden of immunisation are encouraged to address inequities in vaccine choices.

Diagnosis of Neurological Infections in Pediatric Patients from Cell-Free DNA Specimens by Using Metagenomic Next-Generation Sequencing

Central nervous system (CNS) infections can cause significant morbidity and mortality, especially in children. Rapid and accurate pathogenic detection in suspected CNS infections is essential for disease control at the early stage of infection. To evaluate the performance of metagenomic next-generation sequencing (mNGS) of cell-free DNA (cfDNA) in cerebrospinal fluid (CSF) in pediatric patients, we retrospectively analyzed the efficiency of cfDNA mNGS in children with CNS infections (n = 257) or noninfectious neurological disorders (n = 81). The CSF samples of 124 random subjects were used to evaluate the accuracy between mNGS of cfDNA and whole-cell DNA (wcDNA). In total, cfDNA mNGS detected a wide range of microbes with a detection rate of 71.0%, and the sensitivity and total coincidence rate with clinical diagnosis reached 68.9% and 67.5%, respectively. Compared with wcDNA mNGS, cfDNA mNGS had a higher efficacy in detecting viruses (66 versus 13) and Mycobacterium (7 versus 1), with significantly higher reads per million. The dominant causative pathogens were bacteria and viruses in CNS infections, but these presented with different pathogen spectra in different age categories. The best timing for the mNGS test ranged from 1 to 6 days after the start of anti-infection therapy, and the earlier mNGS started, the better was identification of bacterial CNS infections. This study emphasized that cfDNA mNGS had overall superiority to conventional methods on causative pathogen detection in pediatric CNS infections, and it was even better than wcDNA mNGS. Furthermore, research needs to be better validated in large-scale clinical trials to improve the clinical applications of cfDNA mNGS. IMPORTANCE Our study emphasized that cfDNA mNGS had overall superiority to conventional methods on causative pathogen detection in CNS-infected children, and it was even better than wcDNA mNGS. cfDNA mNGS detected a wide range of pathogens with a high total coincidence rate (67.5%) against clinical diagnosis. The best timing for cfDNA mNGS detection ranged from 1 to 6 days, rather than 0 days, after the start of empirical anti-infection therapy. The earlier mNGS started, the better the identifications of bacterial CNS infections. To the best of our knowledge, this research is the first report evaluating the clinical utility of mNGS with different methods (cfDNA versus wcDNA) of extracting DNA from CSF specimens in diagnosing pediatric CNS infections. Meanwhile, this is the largest cohort study that has evaluated the performance of mNGS using cfDNA from CSF specimens in pediatric patients with CNS infections.

Vaccination following the expanded programme on immunization schedule could help to reduce deaths in children under five hospitalized for pneumonia and severe pneumonia in a developing country

Background

Worldwide, pneumonia is the leading cause of mortality in children under the age of five. An expanded program on immunization (EPI) is one kind of evidence-based tool for controlling and even eradicating infectious diseases.

Objectives

This study aimed to explore the impact of EPI vaccination, including BCG, DPT-Hib-Hep B, OPV, IPV, and PCV-10, among children from the age of 4 to 59 months hospitalized for pneumonia and severe pneumonia. Additionally, we evaluated the role of 10 valent pneumococcal conjugate vaccines alone on clinical outcomes in such children.

Methods

In this retrospective chart review, children from the age of 4 to 59 months with WHO-defined pneumonia and severe pneumonia admitted to the Dhaka Hospital of the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b) between August 2013 and December 2017 who had the information on immunization as per EPI schedule by 4 months of age were included in the analysis. A comparison was made between the children who were fully immunized (immunization with BCG, DPT-Hib-Hep B, OPV, and IPV from 2013 to 2015 and PCV-10 from 2015 to 2017) and who were not immunized (consisting of partial immunization and no immunization) during the study period.

Results

A total of 4,625 children had pneumonia and severe pneumonia during the study period. Among them, 2,605 (56.3%) had received the information on immunization; 2,195 (84.3%) were fully immunized by 4 months of age according to the EPI schedule and 410 were not immunized. In the log-linear binomial regression analysis, immunization of children from 4 to 59 months of age was found to be associated with a lower risk of diarrhea (p = 0.033), severe pneumonia (p = 0.001), anemia (p = 0.026), and deaths (p = 0.035). Importantly, the risk of developing severe pneumonia (1054/1,570 [67%] vs. 202/257 [79%], p < 0.001) and case-fatality rate (57/1,570 [3.6%] vs. 19/257 [7.4%], p = 0.005) was still significantly lower among those who were immunized with PCV-10 than those who were not.

Conclusion

Children immunized as per the EPI schedule were at a lower risk of diarrhea, severe pneumonia, anemia, and death, compared to unvaccinated children. In addition, PCV-10 was found to be protective against severe pneumonia and deaths in vaccinated children. The overall results underscored the importance of the continuation of immunization, scrupulously adhering to the EPI schedule to reduce the risk of morbidities and mortalities in children, especially in resource-limited settings.

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.

Theories-based determinants analysis of Hib-combined vaccine hesitancy in China: A multi-group structural equation modeling

OBJECTIVES

To explore determinants of Hib-combined vaccine hesitancy in Chinese parents, and to provide scientific intervention measures to tackle vaccine hesitancy.

METHODS

2,531 parents were recruited from local healthcare centers in Zhejiang Province by accidental sampling, and completed the self-developed online questionnaire with voluntary participation. Health Belief Model and Model of Determinants of Vaccine Hesitancy were applied to construct the framework of research. Multi-group Structural Equation Modeling was performed to explore the effects of determinants of vaccine hesitancy across various socio-economic status (SES).

RESULTS

Hib-combined vaccine hesitancy for total sample was 2.184 ± 0.777 (95%CI: 2.153-2.214), and most of them were in low (n = 1436, 56.7%) level. Low SES group (2.335 ± 0.763, 95%CI: 2.271-2.400) had significantly highest vaccine hesitancy. For total sample, Self-Efficacy and Cues to Action presented -0.517 and -0.437 of standard total effect on Vaccine Hesitancy, respectively. The Multi-group Structural Equation Model with satisfying goodness of fit in SES groups (χ2 = 1616.074, df = 314, χ2/df = 5.147, CFI = 0.973, TLI = 0.966, SRMR = 0.027, RMSEA = 0.041) showed that Cues to Action imposed -0.621 (95%CI: -0.867-0.389, p < .001) of major standard total effect on Vaccine Hesitancy in low SES group, while Self-Efficacy imposed -0.560 (95%CI: -0.668-0.444, p < .001) and -0.685 (95%CI: -0.841-0.454, p < .001) of principal standard total effect on Vaccine Hesitancy in middle and high SES groups, respectively.

CONCLUSIONS

Hib-combined vaccine hesitancy in Chinese parents was low, and the lower the SES, the higher the vaccine hesitancy. Cues to Action and Self-Efficacy played primary role in declining vaccine hesitancy for parents at low SES, and at middle and high SES, respectively.

Vaccine hesitancy and receipt of mandatory and optional pediatric vaccines in Shanghai, China

Given increased global concern about vaccine hesitancy, this study estimates coverage of mandatory vs non-mandatory vaccines in children, and assesses whether vaccine hesitancy among young parents relates to their child's eventual vaccination status in Shanghai, China. In a cohort study within Shanghai, China, we ascertained vaccine hesitancy among parents of young infants, and later abstracted their child's electronic immunization records. We measure full coverage of vaccines on the mandatory, and publicly funded Expanded Program on Immunization (EPI). Non-EPI vaccines included pneumococcal conjugate vaccine, Haemophilus influenzae type b vaccine, and rotavirus vaccine. Vaccine hesitancy was linked to vaccine uptake through mixed effects logistic regression models. Among 972 children, full coverage of all EPI vaccines by 15 months was 95%, compared to dose 1 coverage of pneumococcal conjugate vaccine at 13%, Haemophilus influenzae type b vaccine at 68%, and rotavirus vaccine at 52%. Vaccine hesitancy was not significantly linked with full coverage of all EPI vaccines (OR: 1.55, 95% CI: .89, 2.72), but coverage in the vaccine hesitant was lower for pneumococcal conjugate vaccine dose 1 (OR: .70, 95% CI: .53, .91), and rotavirus vaccine dose 1 (OR: .69, 95% CI: .56, .86). Disparities by education level were not significant for EPI vaccines, but were for dose 1 of pneumococcal conjugate vaccine rotavirus vaccine. Overall, vaccine hesitancy was related to lower uptake of non-EPI, but not EPI vaccines. Shanghai has a robust system for insurance equitable access to EPI vaccines, but if vaccine hesitancy grows, it could reduce coverage of non-EPI vaccines.

Parental preference for Haemophilus influenzae type b vaccination in Zhejiang Province, China: A discrete choice experiment

Background

China is the only country in the world that has not included the Haemophilus influenzae type b (Hib) vaccine in its National Immunization Program, making it more difficult to eliminate Hib-related diseases through Hib vaccination. It is necessary to study parental preferences for Hib vaccination to optimize vaccine promotion strategies in China.

Objective

This study aimed to investigate Chinese parental preference for five attributes of Hib vaccination, i.e., the place of origin, effectiveness, adverse event, doctors' recommendation, and the price of full vaccination when making a decision to vaccinate their children under 2 years old.

Methods

A cross-sectional survey was conducted in two cities in Zhejiang Province from November to December in 2020 using a discrete choice experiment (DCE). A mixed logit model was used to estimate participating parents' preference for Hib vaccination attributes included in the DCE. Subgroup analysis and probability analysis were also conducted to capture the heterogeneity and trade-off of parental preference for Hib vaccination.

Results

Data from 6,168 observations were included in the analyses. Parents of children are, on average, more likely to voice a positive preference for Hib vaccination. Such attributes of Hib vaccination as effectiveness and doctor's recommendation have a significant positive influence on parents' preference for Hib vaccination, while imported vaccines, adverse events, and the price of full vaccination have a significant negative influence on parents' preference. Parents with different demographic characteristics also existed heterogeneities in preference for Hib vaccination. Parents will make a trade-off on price if the Hib vaccine has a good performance on effectiveness and safety.

Conclusion

The study found that, regardless of the place of origin of the Hib vaccine, parents with children under 2 years old prefer to compromise on price if the vaccine has a better effectiveness and safety profile. A proactive recommendation from doctors would strengthen their willingness for Hib vaccination. These findings help aid the development of communication strategies with parents for Hib vaccination in China.

Nasopharyngeal aspirates in children with severe community-acquired pneumonia collected within 3 days before bronchoscopy can partially reflect the pathogens in bronchoalveolar lavage fluids

BACKGROUND

There is little evidence about consistency between nasopharyngeal and pulmonary pathogens in children with severe pneumonia. This study aims to compare the difference of pathogens between nasopharyngeal aspirates (NPAs) collected before bronchoscopy and bronchoalveolar lavage fluids (BALFs) in children with severe community-acquired pneumonia (SCAP).

METHODS

NPAs and BALFs were collected form pediatric SCAP cases hospitalized from January 2018 to March 2019. NPAs were colleced within 3 days before bronchoscopy. Samples were detected by direct immunofluorescence assay (DFA) for seven respiratory viruses and by routine bacterial culture in the clinical microbiology laboratory. Respiratory syncytial virus (RSV), Adenovirus (ADV), Influenza virus types A, B (IV-A and IV-B), Parainfluenza virus 1-3 (PIV1-3) were detected with a commercial assay. The virological and bacteriological detention results of NPAs were compared with the results of BALFs.

RESULTS

In total 204 cases with mean age of 3.4 ± 2.8 years (IQR, 1 month-14 years) were included in the study. Both NPA and BALF were collected from those cases. The positive rates of pathogen in NPAs and BALFs were 25.0% (51/204) and 36.7% (75/204), respectively (x² = 6.614, P = 0.010). Respiratory viruses were found in 16.1% (33/204) from NPAs and 32.3% (66/204) from BALFs (x² = 14.524, P < 0.001). RSV and ADV were the two most frequent detected viruses in NPAs and BALFs. High consistentcy of pathogens between NPAs and BALFs was observed, and 96.9% (32/33) viruses detected in NPAs were also found in BALFs. While bacteria were isolated from 12.7% (26/204) and 10.7% (22/204) of the two kinds of samples, respectively (x² = 0.378, P = 0.539). In addition, Haemophilus influenzae (HI) was the dominant germ in both samples.

CONCLUSION

The DFA method used to detect seven respiratory viruses from NPAs collected within 3 days before bronchoscopy can partially reflect the pathogens in the lungs in children with SCAP.

The prevalence and influencing factors of the oropharyngeal carriage of Haemophilus influenzae in healthy children in a high-altitude area of China: A cross-sectional study

Haemophilus influenzae is a common commensal organism of the human upper respiratory tract and an important cause of human disease. No data on H influenzae carriage rate has been carried out on the Qinghai-Tibet Plateau of China. This study aims to present the H influenzae carriage rate and influencing factors of H influenzae in healthy children <15 years of age in Qinghai Province, an area located on the Qinghai-Tibet Plateau in China. Oropharyngeal swabs for the detection of H influenzae DNA were collected between September and October 2019. Taqman real-time polymerase chain reaction was used to detect the nucleic acids from the oropharyngeal swabs. Self-designed questionnaires were used to investigate the related information among this group of children. A number of 284 children were enrolled in this study. The carriage rate of H influenzae was 44.7%. The carriage rate in cities was 47.5%, in rural areas was 21.9%, and in pastoral areas was 52.8%. The carriage rate was found to be higher among children of minority ethnic groups than those of Han ethnicity (55.6% vs 38.1%). H influenzae carriage rate was influenced by tobacco smoke exposure (adjusted odds ratio [aOR] = 2.31, 95% CI [confidence interval]: 1.14-4.70), having siblings <5 years of age (aOR = 2.36, 95% CI: 1.21-4.59), respiratory infections during the last 30 days (aOR = 2.37, 95% CI: 1.11-5.06), and parent/guardian education level (aOR = 0.08, 95% CI: 0.02-0.27). H influenzae was highly prevalent in healthy children in Qinghai Province, especially among children of minority ethnicities and those living in pastoral areas. Tobacco smoke exposure, having siblings <5 years of age, and respiratory infections during the last 30 days were risk factors for H influenzae carriage. Parents or guardians having education levels of college or higher was a protective factor for H influenzae carriage. It is of critical importance that the government take effective measures to reduce the carriage rate and the occurrence of H influenzae related diseases in susceptible populations.

Molecular epidemiology and antibiotic resistance profiles of invasive Haemophilus influenzae from Norway 2017–2021

Invasive Haemophilus influenzae (Hi) disease has decreased in countries that included Hi type b (Hib) vaccination in their childhood immunization programs in the 1990s. Non-typeable (NT) and non-b strains are now the leading causes of invasive Hi disease in Europe, with most cases reported in young children and the elderly. Concerningly, no vaccines toward such strains are available and beta-lactam resistance is increasing. We describe the epidemiology of invasive Hi disease reported to the Norwegian Surveillance System for Communicable Diseases (MSIS) (2017–2021, n = 407). Whole-genome sequencing (WGS) was performed on 245 isolates. We investigated the molecular epidemiology (core genome phylogeny) and the presence of antibiotic resistance markers (including chromosomal mutations associated with beta-lactam or quinolone resistance). For isolates characterized with both WGS and phenotypic antibiotic susceptibility testing (AST) (n = 113) we assessed correlation between resistance markers and susceptibility categorization by calculation of sensitivity, specificity, and predictive values. Incidence rates of invasive Hi disease in Norway ranged from 0.7 to 2.3 per 100,000 inhabitants/year (mean 1.5 per 100,000) and declined during the COVID-19 pandemic. The bacterial population consisted of two major phylogenetic groups with subclustering by serotype and multi-locus sequence type (ST). NTHi accounted for 71.8% (176). The distribution of STs was in line with previous European reports. We identified 13 clusters, including four encapsulated and three previously described international NTHi clones with blaTEM–1 (ST103) or altered PBP3 (rPBP3) (ST14/IIA and ST367/IIA). Resistance markers were detected in 25.3% (62/245) of the isolates, with blaTEM–1 (31, 50.0%) and rPBP3 (28, 45.2%) being the most frequent. All isolates categorized as resistant to aminopenicillins, tetracycline or chloramphenicol possessed relevant resistance markers, and the absence of relevant substitutions in PBP3 and GyrA/ParC predicted susceptibility to cefotaxime, ceftriaxone, meropenem and quinolones. Among the 132 WGS-only isolates, one isolate had PBP3 substitutions associated with resistance to third-generation cephalosporins, and one isolate had GyrA/ParC alterations associated with quinolone resistance. The detection of international virulent and resistant NTHi clones underlines the need for a global molecular surveillance system. WGS is a useful supplement to AST and should be performed on all invasive isolates.

Epidemiology and burden of Haemophilus influenzae disease in Thai children before implementation of the routine immunisation programme: A National Health Data Analysis

OBJECTIVES

To conduct the first pre-Haemophilus influenzae (Hi) type b (Hib) immunisation programme-based epidemiological study using national health data.

METHODS

We analysed National Health Security Office data, which cover 72% of the Thai population. The study population included children aged <18 years admitted for Hi disease from 2015 to 2019. Hi disease diagnosis and death were based on the International Statistical Classification of Diseases and Related Health Problems (10th revision) hospital discharge summary codes. We estimated the hospital cost per admission using diagnosis-related grouping with a global budget.

RESULTS

A total of 1125 children aged <18 years were admitted for Hi disease. During the 5-year-study, the annual incidence of Hi disease varied from 1.5 to 1.9 per 100,000 children, with an overall case fatality rate (CFR) of 2%. Pneumonia was the most common clinical form, followed by meningitis and sepsis. The incidence, clinical forms and severity of Hi disease were age specific. Infant CFR was higher than that of other age groups. The incidence of Hi disease in children aged <5 years was 4.9 per 100,000 (CFR = 2.0%). Sepsis was the primary cause of infant death, whereas pneumonia was the cause of death in children aged >5 years. The hospital cost ranged from 25,000 to 30,000 THB per admission.

CONCLUSIONS

This analysis provided epidemiological data of Hi in Thai children before the Hib routine immunisation programme. The incidence of Hi disease was lower than that previously speculated. Our results could facilitate an assessment of the impact of Hib immunisation programme in Thailand.

National, regional, and provincial disease burden attributed to Streptococcus pneumoniae and Haemophilus influenzae type b in children in China: Modelled estimates for 2010-17

Background

Vaccination against Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae type b (Hib) is not included in China's national immunization programme. To inform China's immunization polices, we estimated annual national, regional, and provincial childhood mortality and morbidity attributable to pneumococcus and Hib in 2010–17.

Methods

We estimated proportions of pneumonia and meningitis deaths and cases attributable to pneumococcus and Hib using evidence from vaccine clinical trials and surveillance studies of bacterial meningitis and pathogen-specific case fatality ratios (CFR). Then we applied the proportions to model provincial-level pneumonia cases and deaths, meningitis deaths and meningitis CFR in children aged 1–59 months, accounting for vaccine coverage. Non-pneumonia, non-meningitis (NPNM) invasive disease cases were derived by applying NPNM meningitis ratios to meningitis estimates.

Findings

In 2010–17, annual pneumococcal deaths fell by 49% from 15 600 (uncertainty range: 10 800–17 300) to 8 000 (5 500–8 900), and Hib deaths fell by 56% from 6 500 (4 500–8 800) to 2 900 (2 000–3 900). Severe pneumococcal and Hib cases decreased by 16% to 218 200 (161 500–252 200) in 2017 and 29% to 49 900 (29 000–99 100). Estimated 2017 national three-dose coverage in private market was 1·3% for PCV and 33·4% for Hib vaccine among children aged 1–59 months. Provinces in the west region had the highest disease burden.

Interpretation

Childhood mortality and morbidity attributable to pneumococcal and Hib has decreased in China, but still substantially varied by region and province. Higher vaccine coverage could further reduce disease burden.

Funding

Bill & Melinda Gates Foundation.

T-independent antigen induces humoral memory through germinal centers

T-dependent humoral responses generate long-lived memory B cells and plasma cells (PCs) predominantly through germinal center (GC) reaction. In human and mouse, memory B cells and long-lived PCs are also generated during immune responses to T-independent antigen, including bacterial polysaccharides, although the underlying mechanism for such T-independent humoral memory is not clear. While T-independent antigen can induce GCs, they are transient and thought to be nonproductive. Unexpectedly, by genetic fate-mapping, we find that these GCs actually output memory B cells and PCs. Using a conditional BCL6 deletion approach, we show memory B cells and PCs fail to last when T-independent GCs are precluded, suggesting that the GC experience per se is important for programming longevity of T-independent memory B cells and PCs. Consistent with the fact that infants cannot mount long-lived humoral memory to T-independent antigen, B cells from young animals intrinsically fail to form T-independent GCs. Our results suggest that T-independent GCs support humoral memory, and GC induction may be key to effective vaccines with T-independent antigen.

Estimating the global and regional burden of meningitis in children caused by Haemophilus influenzae type b: A systematic review and meta-analysis

Background

Haemophilus influenzae Type B (Hib) meningitis caused significant public health concern for children. Recent assessment in 2015 suggests vaccination has virtually eliminated invasive Hib diseases. However, many countries launched their programs after 2010, and few are yet to establish routine Hib immunisations. We therefore aimed to update the most recent global burden of Hib meningitis before the impact of COVID-19 pandemic, from 2010 to 2020, in order to aid future public health policies on disease management and prevention.

Methods

Epidemiological data regarding Hib meningitis in children <5 years old were systematically searched and evaluated from PubMed and Scopus in August, 2020. We included studies published between 2010 and 2019 that reported incidence, prevalence, mortality, or case-fatality-ratio (CFR), and confirmation of meningitis by cerebrospinal fluid culture, with a minimum one year study period and ten cases. Each data was stratified by one study-year. Median study-year was used if information was not available. Quality of all studies were assessed using our adapted assessment criteria from Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from National Heart, Lung and Blood Institute (NHLBI). We constructed and visually inspected a funnel plot of standard error by the incidence rate and performed an Egger’s regression test to statistically assess publication bias. To ascertain incidence and CFR, we performed generalised linear mixed models on crude individual study estimates. Heterogeneity was assessed using I-squared statistics whilst further exploring heterogeneity by performing subgroup analysis.

Results

33 studies were identified. Pooled incidence of global Hib meningitis in children was 1.13 per 100 000-child-years (95% confidence interval (CI) = 0.80-1.59). Southeast Asian Region (SEAR) of World Health Organisation (WHO) region reported the highest incidence, and European Region (EUR) the lowest. Considering regions with three or more data, Western Pacific Region (WPR) had the highest incidence rate of 5.22 (95% CI = 3.12-8.72). Post-vaccination incidence (0.67 cases per 100 000-child-years, 95% CI = 0.48-0.94) was dramatically lower than Pre-vaccination incidence (4.84 cases per 100 000-child-years, 95% CI = 2.95-7.96). Pooled CFR in our meta-analysis was 11.21% (95% CI = 7.01-17.45). Eastern Mediterranean Region (EMR) had the highest CFR (26.92, 95% CI = 13.41-46.71) while EUR had the lowest (4.13, 95% CI = 1.73-9.54). However, considering regions with three or more data, African Region (AFR) had the highest CFR at 21.79% (95% CI = 13.65-32.92). Before the coronavirus disease 2019 (COVID-19) impact, the estimation for global Hib meningitis cases in 2020 is 7645 and 857 deaths.

Conclusions

Global burden of Hib meningitis has markedly decreased, and most regions have implemented vaccination programs. Extrapolating population-at-risk from studies has possibly led to an underestimation. Continuous surveillance is necessary to monitor vaccination impact, resurgence, vaccine failures, strain variance, COVID-19 impact, and to track improvement of regional and global Hib meningitis mortality.

Assessment of surveillance predictors for suspected respiratory syncytial virus, influenza and Streptococcus pneumoniae infections in children aged <5 years in Madagascar

•

A sensitive surveillance case definition can be defined based on specific symptoms.

•

Intercostal recession and dyspnoea may be used to identify children with respiratory syncytial virus (RSV) infection.

•

Fever was not necessarily a good predictor of paediatric RSV infection.

•

Headache may be used to identify influenza infection in children.

•

Sweats and productive cough may define infection due to Streptococcus pneumoniae in children.

Background

The lack of rapid, sensitive and affordable diagnostic tests that can distinguish a wide variety of respiratory pathogens at the point of care is an obstacle to the rapid implementation of control measures following events and epidemics. In addition, the absence of a standardized case definition to differentiate putative aetiologies is a challenge to assessing the burden of disease. This study aimed to identify the clinical spectrum of respiratory pathogens commonly associated with respiratory tract infections in the context of disease surveillance.

Methods

Data obtained from prospective hospital-based severe acute respiratory infection surveillance among children aged <5 years from November 2010 to July 2013 were used in this study.

Results

Intercostal recession and dyspnoea were predictive of respiratory syncytial virus (RSV) infection, whereas headache and chills were more often observed during influenza A infection. Male patients were at a higher risk for RSV infection than female patients. Productive cough, chills, sweating and weight loss were significantly associated with Streptococcus pneumoniae infection. The presence of fever did not necessarily indicate RSV infection.

Conclusions

Combined with other examinations, this study shows the value of including the syndromic approach in the panel of diagnostic criteria for rapid identification of the risk of infectious diseases in areas where laboratory diagnostics are challenging. Given the current situation with coronavirus disease 2019, this approach may help decision makers to implement appropriate control measures.

Comparative Metabolic Pathways Analysis and Subtractive Genomics Profiling to Prioritize Potential Drug Targets Against Streptococcus pneumoniae

Streptococcus pneumoniae is a notorious pathogen that affects ∼450 million people worldwide and causes up to four million deaths per annum. Despite availability of antibiotics (i.e., penicillin, doxycycline, or clarithromycin) and conjugate vaccines (e.g., PCVs), it is still challenging to treat because of its drug resistance ability. The rise of antibiotic resistance in S. pneumoniae is a major source of concern across the world. Computational subtractive genomics is one of the most applied techniques in which the whole proteome of the bacterial pathogen is gradually reduced to a limited number of potential therapeutic targets. Whole-genome sequencing has greatly reduced the time required and provides more opportunities for drug target identification. The goal of this work is to evaluate and analyze metabolic pathways in serotype 14 of S. pneumonia to identify potential drug targets. In the present study, 47 potent drug targets were identified against S. pneumonia by employing the computational subtractive genomics approach. Among these, two proteins are prioritized (i.e., 4-oxalocrotonate tautomerase and Sensor histidine kinase uniquely present in S. pneumonia) as novel drug targets and selected for further structure-based studies. The identified proteins may provide a platform for the discovery of a lead drug candidate that may be capable of inhibiting these proteins and, therefore, could be helpful in minimizing the associated risk related to the drug-resistant S. pneumoniae. Finally, these enzymatic proteins could be of prime interest against S. pneumoniae to design rational targeted therapy.

Surveillance on the adverse events following immunization with the pentavalent vaccine in Zhejiang, China

Objectives

The aim of this study is to describe the reporting rate of adverse events following immunization (AEFI) with pentavalent vaccine: diphtheria-pertussis-tetanus-poliomyelitis-Haemophilus influenzae type b (DPT-IPV/Hib), and to determine whether the reporting rate of AEFI following DPT-IPV/Hib was higher than the average level of the other vaccines.

Methods

Review and describe the AEFI reported to national adverse event following immunization surveillance system (NAEFISS) in Zhejiang province from 2015 to 2020. Reporting rates of AEFI were calculated by age, city, severity of AEFI, categories of AEFI, and reaction categories. The data mining algorithm used in this study was reporting odds ratio (ROR). A value of ROR‑1.96SE >1 (standard error [SE]) was considered as positive signal.

Results

NAEFISS received 5726 AEFI reports following DTP-IPV/Hib, with a reporting rate of 20.01/10000 doses. Of the reported AEFI, 202 were serious vaccine product-related reactions, including two cases of anaphylactic shock, five cases of Guillain Barre Syndrome (GBS) and two cases of acute disseminated encephalomyelitis. The reporting rate of fever/redness/induration was the highest among all the clinical diagnosis (14.97/10000 doses). The positive signals were obtained for allergic rash (ROR-1.96SE: 1.36), febrile convulsion (ROR-1.96SE: 1.32) and GBS (ROR-1.96SE: 1.16).

Conclusion

The present findings bolstered that the DTP-IPV/Hib administered as the four-dose schedule was generally well tolerated in Chinese infants as we did not identify any new/unexpected safety concern from the NAEFISS during a six-year timespan.

Infection in the Developing Brain: The Role of Unique Systemic Immune Vulnerabilities

Central nervous system (CNS) infections remain a major burden of pediatric disease associated with significant long-term morbidity due to injury to the developing brain. Children are susceptible to various etiologies of CNS infection partly because of vulnerabilities in their peripheral immune system. Young children are known to have reduced numbers and functionality of innate and adaptive immune cells, poorer production of immune mediators, impaired responses to inflammatory stimuli and depressed antibody activity in comparison to adults. This has implications not only for their response to pathogen invasion, but also for the development of appropriate vaccines and vaccination strategies. Further, pediatric immune characteristics evolve across the span of childhood into adolescence as their broader physiological and hormonal landscape develop. In addition to intrinsic vulnerabilities, children are subject to external factors that impact their susceptibility to infections, including maternal immunity and exposure, and nutrition. In this review we summarize the current evidence for immune characteristics across childhood that render children at risk for CNS infection and introduce the link with the CNS through the modulatory role that the brain has on the immune response. This manuscript lays the foundation from which we explore the specifics of infection and inflammation within the CNS and the consequences to the maturing brain in part two of this review series.

Impact of Vaccination on Haemophilus influenzae Type b Carriage in Healthy Children Less Than 5 Years of Age in an Urban Population in Nepal

Background

Reduction in detection of asymptomatic carriage of Haemophilus influenzae type b (Hib) can be used to assess vaccine impact. In Nepal, routine vaccination against Hib in children at 6, 10, and 14 weeks of age was introduced in 2009. Before vaccine introduction, Hib carriage was estimated at 5.0% among children aged <13 years in Nepal, with higher rates among children under 5. Large-scale evaluation of Hib carriage in children has not been investigated since the introduction of the pentavalent diphtheria-tetanus-pertussis/Hib/hepatitis B (DTP-Hib-HepB) vaccine in Nepal.

Methods

A total of 666 oropharyngeal swabs were collected between August and December 2018 from healthy children between 6 months and 5 years of age attending the vaccination clinic at Patan Hospital, Kathmandu, Nepal. Of these 666 swabs, 528 (79.3%) were tested for Hib by culture. Demographic and vaccination data were collected.

Results

Among 528 swabs tested for Hib, 100% came from fully vaccinated children. No swabs were positive for Hib (95% confidence interval, .0–.7). The absence of Hib in 2018 suggests vaccine-induced protection against Hib carriage 9 years after vaccine introduction.

Conclusions

Following 3 doses of pentavalent DTP-Hib-HepB vaccine, Hib carriage in children under the age of 5 years in Nepal is no longer common. Ongoing high coverage with Hib vaccine in early childhood is expected to maintain protection against Hib disease in Nepal.

The Burden of Invasive Bacterial Disease and the Impact of 10-Valent Pneumococcal Conjugate Vaccine in Children <5 years hospitalized for Meningitis in Lusaka, Zambia, 2010-2019

BACKGROUND

Despite the availability of vaccines, invasive bacterial diseases remain a public health concern and cause childhood morbidity and mortality. We investigated the characteristics of etiological agents causing bacterial meningitis in children <5 years in the years pre- (2010-2012) and post- (2014-2019) 10-valent pneumococcal conjugate vaccine (PCV10) introduction in Zambia.

METHODS

Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hi), and Neisseria meningitidis (Nm) from cerebrospinal fluid (CSF) were identified by microbiological culture and/or real-time polymerase chain reaction.

RESULTS

During the surveillance period, a total of 3811 children were admitted with suspected meningitis, 16% (598 of 3811) of which were probable cases. Bacterial meningitis was confirmed in 37% (221 of 598) of the probable cases. Spn pneumoniae, Hi, and Nm accounted for 67% (148 of 221), 14% (31 of 221), and 19% (42 of 221) of confirmed cases, respectively. Thirty-six percent of pneumococcal meningitis was caused by 10-valent pneumococcal conjugate vaccine (PCV10) serotypes, 16% 13-valent pneumococcal conjugate vaccine and 39% by nonvaccine serotype (NVS). There was an association between the introduction of PCV10 vaccination and a decrease in both Spn meningitis and the proportion of PVC10 serotypes in the postvaccination period. Antimicrobial susceptibility of 47 Spn isolates revealed 34% (16 of 47) penicillin resistance. The 31 serotyped Hi accounted for 74% type b (Hib) and 10% type a (Hia). All 42 serogrouped Nm belonged to serogroup W.

CONCLUSIONS

There was a decline in pneumococcal meningitis and proportion of PCV10 serotypes in the postvaccination period. However, the serotype replacement with non-PCV10 serotypes and penicillin resistance warrant continued surveillance to inform policy.

National and provincial impact and cost-effectiveness of Haemophilus influenzae type b conjugate vaccine in China: a modeling analysis

BACKGROUND

Globally, Haemophilus influenzae type b (Hib) vaccine has substantially reduced the burden of Hib invasive disease. However, China remains the only country not to include Hib vaccine into its national immunization program (NIP), although it accounts for 11% of global Hib deaths. We aimed to assess the cost-effectiveness of including Hib vaccine in China's NIP at the national and provincial levels.

METHODS

Using a decision-tree Markov state transition model, we estimated the cost-effectiveness of Hib vaccine in the NIP compared to the status quo of Hib vaccine in the private market for the 2017 birth cohort. Treatment costs and vaccine program costs were calculated from Chinese Center for Disease Control and Prevention (CDC) and national insurance databases. Epidemiological data and other model parameters were obtained from published literature. Cases and deaths averted, quality-adjusted life years (QALYs) gained, and incremental cost-effectiveness ratios (ICER) were predicted by province. Deterministic and probabilistic sensitivity analyses were performed to explore model uncertainty.

RESULTS

Including Hib vaccine in the NIP was projected to prevent approximately 2700 deaths (93% reduction) and 235,700 cases of Hib disease (92% reduction) for the 2017 birth cohort at the national level. Hib vaccine was cost-effective nationally (US$ 8001 per QALY gained) compared to the GDP per capita and cost-effective in 15 of 31 provinces. One-way and scenario sensitivity analyses indicated results were robust when varying model parameters, and in probabilistic sensitivity analysis, Hib vaccine had a 64% probability of being cost-effective nationally.

CONCLUSION

Introducing Hib vaccine in China's NIP is cost-effective nationally and in many provinces. Less socioeconomically developed provinces with high Hib disease burden and low access to Hib vaccine in the current private market, such as those in the west region, would benefit the most from adding Hib vaccine to the NIP. In the absence of a national policy decision on Hib vaccine, this analysis provides evidence for provincial governments to include Hib vaccine into local immunization programs to substantially reduce disease burden and treatment costs.

Lives saved with vaccination for 10 pathogens across 112 countries in a pre-COVID-19 world

Background

Vaccination is one of the most effective public health interventions. We investigate the impact of vaccination activities for Haemophilus influenzae type b, hepatitis B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, rotavirus, rubella, Streptococcus pneumoniae, and yellow fever over the years 2000-2030 across 112 countries.

Methods

Twenty-one mathematical models estimated disease burden using standardised demographic and immunisation data. Impact was attributed to the year of vaccination through vaccine-activity-stratified impact ratios.

Results

We estimate 97 (95%CrI[80, 120]) million deaths would be averted due to vaccination activities over 2000-2030, with 50 (95%CrI[41, 62]) million deaths averted by activities between 2000 and 2019. For children under-5 born between 2000 and 2030, we estimate 52 (95%CrI[41, 69]) million more deaths would occur over their lifetimes without vaccination against these diseases.

Conclusions

This study represents the largest assessment of vaccine impact before COVID-19-related disruptions and provides motivation for sustaining and improving global vaccination coverage in the future.

Funding

VIMC is jointly funded by Gavi, the Vaccine Alliance, and the Bill and Melinda Gates Foundation (BMGF) (BMGF grant number: OPP1157270 / INV-009125). Funding from Gavi is channelled via VIMC to the Consortium's modelling groups (VIMC-funded institutions represented in this paper: Imperial College London, London School of Hygiene and Tropical Medicine, Oxford University Clinical Research Unit, Public Health England, Johns Hopkins University, The Pennsylvania State University, Center for Disease Analysis Foundation, Kaiser Permanente Washington, University of Cambridge, University of Notre Dame, Harvard University, Conservatoire National des Arts et Métiers, Emory University, National University of Singapore). Funding from BMGF was used for salaries of the Consortium secretariat (authors represented here: TBH, MJ, XL, SE-L, JT, KW, NMF, KAMG); and channelled via VIMC for travel and subsistence costs of all Consortium members (all authors). We also acknowledge funding from the UK Medical Research Council and Department for International Development, which supported aspects of VIMC's work (MRC grant number: MR/R015600/1).JHH acknowledges funding from National Science Foundation Graduate Research Fellowship; Richard and Peggy Notebaert Premier Fellowship from the University of Notre Dame. BAL acknowledges funding from NIH/NIGMS (grant number R01 GM124280) and NIH/NIAID (grant number R01 AI112970). The Lives Saved Tool (LiST) receives funding support from the Bill and Melinda Gates Foundation.This paper was compiled by all coauthors, including two coauthors from Gavi. Other funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.

Etiologic Profile of Childhood Stroke from North India: Is It Different from Developed World?

OBJECTIVE

To describe the etiology of childhood arterial-ischemic stroke from a developing country and assess short-term neurologic outcome.

METHODS

Prospective observational study. Consecutive children between the age of >28 days to <12 years, admitted with the diagnosis of arterial-ischemic stroke were enrolled during the study period from January 2017 to December 2018. Short-term neurologic outcome was assessed with Pediatric Cerebral Performance Category (PCPC) scale and Pediatric Stroke Outcome Measure (PSOM).

RESULTS

We enrolled 76 children with arterial-ischemic stroke, with a median age of 24 months (interquartile range 12-69), and 43 (57%) were boys. The most common risk factor for childhood arterial-ischemic stroke was arteriopathy in 59 (77%), followed by cardiovascular disorder in 12 (16%) children. Among 59 children with arteriopathy, 32 (42%) had infection-associated arteriopathies, 10 (13%) had mineralizing angiopathy, 10 (13%) had moyamoya disease. Pediatric stroke risk factors were classified according to Pediatric Stroke Classification and CASCADE primary classification. Short-term neurologic outcome was assessed at 3 months in 62 (82%) survivors. Among stroke survivors, 33 (61%) had sensory-motor deficits, and 24 (39%) had severe neurologic disability (PCPC ≥ 4). The presence of fever, encephalopathy, low Glasgow coma score at presentation, seizures, and infection-associated arteriopathy predicted severe neurologic disability at follow-up.

CONCLUSION

The risk factors for pediatric arterial-ischemic stroke are different from developed countries in our cohort. Infection-associated arteriopathies, mineralizing angiopathy, and moyamoya disease are the most common risk factors in our cohort. Two-thirds of pediatric stroke survivors have neurologic disability at short-term follow-up.

Invasive Haemophilus influenzae Infections after 3 Decades of Hib Protein Conjugate Vaccine Use

Haemophilus influenzae serotype b (Hib) was previously the most common cause of bacterial meningitis and an important etiologic agent of pneumonia in children aged <5 years. Its major virulence factor is the polyribosyl ribitol phosphate (PRP) polysaccharide capsule. In the 1980s, PRP-protein conjugate Hib vaccines were developed and are now included in almost all national immunization programs, achieving a sustained decline in invasive Hib infections. However, invasive Hib disease has not yet been eliminated in countries with low vaccine coverage, and sporadic outbreaks of Hib infection still occur occasionally in countries with high vaccine coverage. Over the past 2 decades, other capsulated serotypes have been recognized increasingly as causing invasive infections. H. influenzae serotype a (Hia) is now a major cause of invasive infection in Indigenous communities of North America, prompting a possible requirement for an Hia conjugate vaccine. H. influenzae serotypes e and f are now more common than serotype b in Europe. Significant year-to-year increases in nontypeable H. influenzae invasive infections have occurred in many regions of the world. Invasive H. influenzae infections are now seen predominantly in patients at the extremes of life and those with underlying comorbidities. This review provides a comprehensive and critical overview of the current global epidemiology of invasive H. influenzae infections in different geographic regions of the world. It discusses those now at risk of invasive Hib disease, describes the emergence of other severe invasive H. influenzae infections, and emphasizes the importance of long-term, comprehensive, clinical and microbiologic surveillance to monitor a vaccine's impact.

Long Term Impact of Conjugate Vaccines on Haemophilus influenzae Meningitis: Narrative Review

H. influenzae serotype b (Hib) used to be the commonest cause of bacterial meningitis in young children. The widespread use of Hib conjugate vaccine has profoundly altered the epidemiology of H. influenzae meningitis. This short review reports on the spectrum of H. influenzae meningitis thirty years after Hib conjugate vaccine was first introduced into a National Immunization Program (NIP). Hib meningitis is now uncommon, but meningitis caused by other capsulated serotypes of H. influenzae and non-typeable strains (NTHi) should be considered. H. influenzae serotype a (Hia) has emerged as a significant cause of meningitis in Indigenous children in North America, which may necessitate a Hia conjugate vaccine. Cases of Hie, Hif, and NTHi meningitis are predominantly seen in young children and less common in older age groups. This short review reports on the spectrum of H. influenzae meningitis thirty years after Hib conjugate vaccine was first introduced into a NIP.

Vaccines to Prevent Meningitis: Historical Perspectives and Future Directions

Despite advances in the development and introduction of vaccines against the major bacterial causes of meningitis, the disease and its long-term after-effects remain a problem globally. The Global Roadmap to Defeat Meningitis by 2030 aims to accelerate progress through visionary and strategic goals that place a major emphasis on preventing meningitis via vaccination. Global vaccination against Haemophilus influenzae type B (Hib) is the most advanced, such that successful and low-cost combination vaccines incorporating Hib are broadly available. More affordable pneumococcal conjugate vaccines are becoming increasingly available, although countries ineligible for donor support still face access challenges and global serotype coverage is incomplete with existing licensed vaccines. Meningococcal disease control in Africa has progressed with the successful deployment of a low-cost serogroup A conjugate vaccine, but other serogroups still cause outbreaks in regions of the world where broadly protective and affordable vaccines have not been introduced into routine immunization programs. Progress has lagged for prevention of neonatal meningitis and although maternal vaccination against the leading cause, group B streptococcus (GBS), has progressed into clinical trials, no GBS vaccine has thus far reached Phase 3 evaluation. This article examines current and future efforts to control meningitis through vaccination.

Etiological and epidemiological characteristics of severe acute respiratory infection caused by multiple viruses and Mycoplasma pneumoniae in adult patients in Jinshan, Shanghai: A pilot hospital-based surveillance study

Background

Severe acute respiratory infection (SARI) results in a tremendous disease burden worldwide. Available research on active surveillance among hospitalized adult patients suffering from SARI in China is limited. This pilot study aimed to identify associated etiologies and describe the demographic, epidemiological and clinical profiles of hospitalized SARI patients aged over 16 years in Jinshan, Shanghai.

Methods

Active surveillance was conducted at 1 sentinel hospital in Jinshan district, Shanghai, from April 2017 to March 2018. Hospitalized SARI patients aged over 16 years old were enrolled, and nasopharyngeal swabs were collected within 24 hours of admission and tested for multiple respiratory viruses (including 18 common viruses) and Mycoplasma pneumoniae with real-time polymerase chain reaction. Demographic, epidemiological and clinical information was obtained from case report forms.

Results

In total, 397 SARI patients were enrolled; the median age was 68 years, and 194 (48.9%) patients were male. A total of 278 (70.0%) patients had at least one underlying chronic medical condition. The most frequent symptoms were cough (99.2%) and sputum production (88.4%). The median duration of hospitalization was 10 days. A total of 250 infection patients (63.0%) were positive for at least one pathogen, of whom 198 (49.9%) were positive for a single pathogen and 52 (13.1%) were positive for multiple pathogens. The pathogens identified most frequently were M. pneumoniae (23.9%, 95/397), followed by adenovirus (AdV) (11.6%, 46/397), influenza virus A/H3N2 (Flu A/H3N2) (11.1%, 44/397), human rhinovirus (HRhV) (8.1%, 32/397), influenza virus B/Yamagata (Flu B/Yamagata) (6.3%, 25/397), pandemic influenza virus A/H1N1 (Flu A/pH1N1) (4.0%, 16/397), parainfluenza virus (PIV) type 1 (2.0%, 8/397), human coronavirus (HCoV) type NL63 (2.0%, 8/397), HCoV 229E (1.5%, 6/397), HCoV HKU1 (1.5%, 6/397), PIV 3 (1.5%, 6/397), human metapneumovirus (HMPV) (1.5%, 6/397), PIV 4 (1.3%, 5/397), HCoV OC43 (1.0%, 4/397), influenza virus B/Victoria (Flu B/Victoria) (0.5%, 2/397), respiratory syncytial virus (RSV) type B (0.5%, 2/397), and human bocavirus (HBoV) (0.3%, 1/397). The seasonality of pathogen-confirmed SARI patients had a bimodal distribution, with the first peak in the summer and the second peak in the winter. Statistically significant differences were observed with respect to the rates of dyspnea, radiographically diagnosed pneumonia and the presence of at least one comorbidity in patients who were infected with only M. pneumoniae, AdV, HRhV, Flu A/H3N2, Flu A /pH1N1 or Flu B/Yamagata. The differences in the positivity rates of the above 6 pathogens among the different age groups were nonsignificant.

Conclusions

M. pneumoniae, AdV and Flu A/H3N2 were the main pathogens detected in hospitalized SARI patients aged over 16 years old in Jinshan district, Shanghai. Our findings highlight the importance of sustained multipathogen surveillance among SARI patients in sentinel hospitals, which can provide useful information on SARI etiologies, epidemiology, and clinical characteristics.

Glycoconjugate Vaccines for Prevention of Haemophilus influenzae Type b Diseases

This review summarizes the experience in laboratory- and industrial-scale syntheses of glycoconjugate vaccines used for prevention of infectious diseases caused by Haemophilus influenzae type b bacteria based on the linear capsular polysaccharide poly-3-β-D-ribosyl-(1→1)-D-ribitol-5-phosphate (PRP) or related synthetic oligosaccharide ligands. The methods for preparation of related oligosaccharide derivatives and results of the studies evaluating effect of their length on immunogenic properties of the conjugates with protein carriers are overviewed.

Identification of Gut Microbiome Signatures in Patients With Post-stroke Cognitive Impairment and Affective Disorder

Stroke (ST), endangering human health due to its high incidence and high mortality, is a global public health problem. There is increasing evidence that there is a link between the gut microbiota (GM) and neuropsychiatric diseases. We aimed to find the GM of ST, post-ST cognitive impairment (PSCI), and post-ST affective disorder (PSTD). GM composition was analyzed, followed by GM identification. Alpha diversity estimation showed microbiota diversity in ST patients. Beta diversity analysis showed that the bacterial community structure segregated differently between different groups. At the genus level, ST patients had a significantly higher proportion of Enterococcus and lower content of Bacteroides, Escherichia-Shigella, and Megamonas. PSCI patients had a significantly higher content of Enterococcus, Bacteroides, and Escherichia-Shigella and a lower proportion of Faecalibacterium compared with patients with ST. Patients with PSTD had a significantly higher content of Bacteroides and Escherichia-Shigella and lower content of Enterococcus and Faecalibacterium. Parabacteroides and Lachnospiraceae were associated with Montreal cognitive assessment score of ST patients. Our study indicated that the characteristic GM, especially Bacteroidetes, could be used as clinical biomarkers of PSCI and PSTD.

Clinical and Molecular Epidemiology of Invasive Haemophilus influenzae Serotype a Infections in Utah Children

BACKGROUND

Following widespread use of the Haemophilus influenzae serotype b (Hib) vaccine, H. influenzae serotype a (Hia) has emerged as an important pathogen in children in some regions. We describe the clinical features and molecular epidemiology of invasive Hia disease in children in Utah over an 11-year period.

METHODS

We identified cases of invasive Hia disease, defined as detection of Hia from a normally sterile site, in children aged <18 years from Utah between 2007 and 2017. Medical records were reviewed to determine demographic characteristics and clinical outcomes. Available Hia isolates were genotyped using multilocus sequence typing, and phylogenetic division was determined using sodC polymerase chain reaction. Presence of the putative virulence-associated IS1016-bexA duplication-deletion was evaluated.

RESULTS

We identified 51 children with invasive Hia. The average annual incidence was 1.7 cases per 100 000 children aged <5 years; 4.8 cases per 100 000 children aged <1 year. The median age was 11.3 months. The most common clinical presentation was meningitis (53%), followed by pneumonia (14%) and septic arthritis (14%). Twenty-two children (43%) required admission to an intensive care unit; 1 died. Sequence type (ST) 62, phylogenetic division II isolates caused 75% (21/28) of disease. No isolates contained the virulence-associated IS1016-bexA duplication-deletion.

CONCLUSIONS

Hia is a significant cause of severe invasive bacterial infection in Utah. The majority of infections were caused by ST62 isolates, a phylogenetic division II Hia type that lacks the IS1016-bexA duplication-deletion. Hia ST62 has not been commonly reported elsewhere, suggesting a unique molecular epidemiology in our population.

Trends and health burden of hospitalized acute respiratory infections and impact of Haemophilus influenza immunization in a Tunisian university hospital: a twelve-year study

BACKGROUND

We aimed to describe the episodes and trends of admissions for community-acquired Respiratory Infections (RI) over a 12-year period and to assess the impact of Haemophilus influenza type b (Hib) vaccine on RI admissions in children aged up to 3 years.

METHODS

We conducted a twelve-year retrospective observational study on all community-acquired RI admitted to Fattouma Bourguiba Hospital in Monastir Governorate (Tunisia) from 1 January 2002 to 31 December 2013. RI cases were selected from the Regional Registry of Hospital Morbidity. Data were coded according to ICD-10. To assess the impact of the Hib vaccine, three cohorts were defined based on vaccine status (unvaccinated cohort, first vaccinated cohort (VC) by monovalent form and second VC by pentavalent combination).

RESULTS

Admissions for RI represented 17.6% (CI95%: 17.3-18.1) of all communicable diseases hospitalizations (n = 6 061/34 289). The crude incidence rates (CIR) per 100,000 inh were 24.2 for upper RI (URI) and 77.5 and for Lower RI (LRI) (p < 0.0001). Pneumonias represented 53.9% of LRI. Sex-ratio (male/female) was 1.12 for URI and 1.64 for LRI (p < 0.0001). At admission, the median age was 22 years (IQR: 3-52). Admission for Pneumonia increased significantly during study period (slope 'b' = 5.16; p < 0.0001) especially in children up to 5 years old (slope 'b' = 5.53) and in elderly (slope 'b' = 2.13). Among children up to 3 years old, the CIRs per 100,000 for Hib pneumonia admission were 11.6 in Non-Vaccinated Cohort (NVC), 10.6 in Vaccinated Cohort (VC) by protocol 1 (Hib Vaccine monovalent) and 0.80 in VC by protocol 2 (pentavalent vaccine combination).The relative risk reduction was 99% for protocol 2 (p < 0.001).

CONCLUSION

Admissions for RI in a  tertiary level hospital were common with an increasing trend. The Hib immunization program, in particular the pentavalent combination, has had a positive impact on the reduction of related acute diseases.

Carriage of Haemophilus influenzae among children attending childcare centres in Kuala Lumpur, Malaysia in the post vaccination era: A cross-sectional study

BACKGROUND

Haemophilus influenzae (H. influenzae) is a human upper respiratory tract colonizer which causes wide range of disease especially in children<5 years old and in the elderly. Although worldwide incidence in industrialised countries where Hib vaccination is commonly used has dropped sharply since implementation of H. influenzae type b (Hib) vaccination, there is limited data on the disease burden caused by H. influenzae in Malaysia post vaccination era. A change in predominant serotype from type b to non-b serotypes of H. influenzae in invasive diseases was reported worldwide. We investigated the carriage of H. influenzae post vaccination era among 2-4 years old.

METHODOLOGY

Randomly, we collected 436 oropharyngeal swabs from healthy children aged 2-4 years in 30 registered childcare centres in Kuala Lumpur (August 2018-May 2019). Informed consent and written questionnaires were obtained from parents. H. influenzae was identified by standard microbiological methods. Univariable analysis was carried out to describe variables associated with colonization. All variables with p < 0.25 were included in multivariable logistic regression model. A p value < 0.05 was considered significant.

RESULTS

A higher carriage rate was noted among the unvaccinated children (4/28; 14.3%) compared to vaccinated children (16/326; 4.9%) but were not statistically significant. The serotypes were type a (9; 37.5%), type b (5; 20.8%), type c (3; 12.5%), type d (2; 8%), type e (1; 4.2%) and type f (4; 16.7%). Variables like age, basic sanitation, immunization status, body mass index were included in multivariable logistic regression test since p values in univariate analysis were<0.25. Planned sewage system was found to be significant (Adjusted OR, 0.06; 95% CI, 0.01-0.46; p = 0.006).

CONCLUSION

Fewer carriage rates were observed among children post Hib vaccination era. Hib carriage is still possible after vaccination. The presence non-b serotypes may imply emerging replacement serotypes.

Microbiological Characterization and Antibiotic Susceptibility Pattern of Haemophilus Influenzae Isolates from a Tertiary Care Centre in South India

Haemophilus are fastidious Gram negative bacilli, which require factor X (hemin), factor V (NAD), or both for their growth. Haemophilus influenzae is the type species, and is considered to be the most pathogenic. They are associated with many invasive infections including meningitis, epiglottitis, pneumonia, and otitis media. Serotype b is most commonly associated with infections. Haemophilus species isolated from patients in a tertiary care centre in South India were studied. Identification, serotyping and biotyping were done and antibiotic susceptibility test was performed. The incidence of H. influenzae infections in our study was 65.3 cases/100,000 persons. Serotype b was the most common (66.67%), followed by non typeable H.influenzae (NTHi) (25%). Most isolates from adults were type b, while all isolates from pediatric population were non typeable. The most common biotype was type II, followed by type I and type III. Three of 24 isolates were β lactamase producers (12.5%). One isolate was β lactamase negative Ampicillin resistant (BLNAR). Resistance to ampicillin was 16.67%. Resistance to cephalosporins and fluoroquinolones was low (4-10%). Co-trimoxazole resistance was found to be very high (75%). All isolates were susceptible to azithromycin, tetracycline, chloramphenicol and meropenem. No isolates of H.influenzae type b were obtained from the paediatric population which may be due to the introduction of Hib vaccine. The increase in resistance to commonly used antibiotics is worrisome, especially penicillins and co-trimoxazole. Use of co-trimoxazole in empirical therapy of upper and lower respiratory tract infections has a high chance of failure in the current scenario.

Declines in Pediatric Bacterial Meningitis in the Republic of Benin Following Introduction of Pneumococcal Conjugate Vaccine: Epidemiological and Etiological Findings, 2011-2016

BACKGROUND

Pediatric bacterial meningitis (PBM) remains an important cause of disease in children in Africa. We describe findings from sentinel site bacterial meningitis surveillance in children <5 years of age in the Republic of Benin, 2011-2016.

METHODS

Cerebrospinal fluid (CSF) was collected from children admitted to Parakou, Natitingou, and Tanguieta sentinel hospitals with suspected meningitis. Identification of Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, and Neisseria meningitidis (meningococcus) was performed by rapid diagnostic tests, microbiological culture, and/or polymerase chain reaction; where possible, serotyping/grouping was performed.

RESULTS

A total of 10 919 suspected cases of meningitis were admitted to the sentinel hospitals. Most patients were 0-11 months old (4863 [44.5%]) and there were 542 (5.0%) in-hospital deaths. Overall, 4168 CSF samples were screened for pathogens and a total of 194 (4.7%) PBM cases were confirmed, predominantly caused by pneumococcus (98 [50.5%]). Following pneumococcal conjugate vaccine (PCV) introduction in 2011, annual suspected meningitis cases and deaths (case fatality rate) progressively declined from 2534 to 1359 and from 164 (6.5%) to 14 (1.0%) in 2012 and 2016, respectively (P < .001). Additionally, there was a gradual decline in the proportion of meningitis cases caused by pneumococcus, from 77.3% (17/22) in 2011 to 32.4% (11/34) in 2016 (odds ratio, 7.11 [95% confidence interval, 2.08-24.30]). Haemophilus influenzae meningitis fluctuated over the surveillance period and was the predominant pathogen (16/34 [47.1%]) by 2016.

CONCLUSIONS

The observed decrease in pneumococcal meningitis after PCV introduction may be indicative of changing patterns of PBM etiology in Benin. Maintaining vigilant and effective surveillance is critical for understanding these changes and their wider public health implications.

Pediatric Bacterial Meningitis Surveillance in the World Health Organization African Region Using the Invasive Bacterial Vaccine-Preventable Disease Surveillance Network, 2011-2016

BACKGROUND

Bacterial meningitis is a major cause of morbidity and mortality in sub-Saharan Africa. We analyzed data from the World Health Organization's (WHO) Invasive Bacterial Vaccine-preventable Diseases Surveillance Network (2011-2016) to describe the epidemiology of laboratory-confirmed Streptococcus pneumoniae (Spn), Neisseria meningitidis, and Haemophilus influenzae meningitis within the WHO African Region. We also evaluated declines in vaccine-type pneumococcal meningitis following pneumococcal conjugate vaccine (PCV) introduction.

METHODS

Reports of meningitis in children <5 years old from sentinel surveillance hospitals in 26 countries were classified as suspected, probable, or confirmed. Confirmed meningitis cases were analyzed by age group and subregion (South-East and West-Central). We described case fatality ratios (CFRs), pathogen distribution, and annual changes in serotype and serogroup, including changes in vaccine-type Spn meningitis following PCV introduction.

RESULTS

Among 49 844 reported meningitis cases, 1670 (3.3%) were laboratory-confirmed. Spn (1007/1670 [60.3%]) was the most commonly detected pathogen; vaccine-type Spn meningitis cases declined over time. CFR was the highest for Spn meningitis: 12.9% (46/357) in the South-East subregion and 30.9% (89/288) in the West-Central subregion. Meningitis caused by N. meningitidis was more common in West-Central than South-East Africa (321/954 [33.6%] vs 110/716 [15.4%]; P < .0001). Haemophilus influenzae (232/1670 [13.9%]) was the least prevalent organism.

CONCLUSIONS

Spn was the most common cause of pediatric bacterial meningitis in the African region even after reported cases declined following PCV introduction. Sustaining robust surveillance is essential to monitor changes in pathogen distribution and to inform and guide vaccination policies.

Hospital-based Surveillance for Pediatric Bacterial Meningitis in the Era of the 13-Valent Pneumococcal Conjugate Vaccine in Ghana

Background

Global surveillance for vaccine preventable invasive bacterial diseases has been set up by the World Health Organization to provide disease burden data to support decisions on introducing pneumococcal conjugate vaccine (PCV). We present data from 2010 to 2016 collected at the 2 sentinel sites in Ghana.

Methods

Data were collected from children <5 years of age presenting at the 2 major teaching hospitals with clinical signs of meningitis. Cerebrospinal fluid specimens were collected and tested first at the sentinel site laboratory with conventional microbiology methods and subsequently with molecular analysis, at the World Health Organization Regional Reference Laboratory housed at the Medical Research Council Unit The Gambia, for identification of Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, the 3 most common bacteria causing meningitis.

Results

There were 4008 suspected cases of meningitis during the surveillance period, of which 31 (0.8%) were laboratory confirmed. Suspected meningitis cases decreased from 923 in 2010 to 219 in 2016. Of 3817 patients with available outcome data, 226 (5.9%) died. S. pneumoniae was the most common bacterial pathogen, accounting for 68.5% of confirmed cases (50 of 73). H. influenzae and N. meningitidis accounted for 6.8% (5 of 73) and 21.9% (16 of 73), respectively. The proportion of pneumococcal vaccine serotypes causing meningitis decreased from 81.3% (13 of 16) before the introduction of 13-valent PCV (2010–2012) to 40.0% (8 of 20) after its introduction (2013–2016).

Conclusions

Cases of suspected meningitis decreased among children <5 years of age between 2010 and 2016, with declines in the proportion of vaccine-type pneumococcal meningitis after the introduction of 13-valent PCV in Ghana.

National, regional, and state-level pneumonia and severe pneumonia morbidity in children in India: modelled estimates for 2000 and 2015

BACKGROUND

The absolute number of pneumonia deaths in India has declined substantially since 2000. However, pneumonia remains a major cause of morbidity in children in the country. We used a risk factor-based model to estimate pneumonia and severe pneumonia morbidity in Indian states in 2000 and 2015.

METHODS

In this modelling study, we estimated the burden of pneumonia and severe pneumonia in children younger than 5 years using a risk factor-based model. We did a systematic literature review to identify published data on the incidence of pneumonia from community-based longitudinal studies and calculated summary estimates. We estimated state-specific incidence rates for WHO-defined clinical pneumonia between 2000 and 2015 using Poisson regression and the prevalence of risk factors in each state was obtained from National Family Health Surveys. From clinical pneumonia studies, we identified studies reporting the proportion of clinical pneumonia cases with lower chest wall indrawing to estimate WHO-defined severe pneumonia cases. We used the estimate of the proportion of cases with lower chest wall indrawing to estimate WHO-defined severe pneumonia cases for each state.

FINDINGS

Between 2000 and 2015, the estimated number of pneumonia cases in Indian HIV-uninfected children younger than 5 years decreased from 83·8 million cases (95% uncertainty interval [UI] 14·0-300·8) to 49·8 million cases (9·1-174·2), representing a 41% reduction in pneumonia cases. The incidence of pneumonia in children younger than 5 years in India was 657 cases per 1000 children (95% UI 110-2357) in 2000 and 403 cases per 1000 children (74-1408) in 2015. The estimated national pneumonia case fatality rate in 2015 was 0·38% (95% UI 0·11-2·10). In 2015, the estimated number of severe pneumonia cases was 8·4 million (95% UI 1·2-31·7), with an incidence of 68 cases per 1000 children (9-257) and a case fatality ratio of 2·26% (0·60-16·30). In 2015, the estimated number of pneumonia cases in HIV-uninfected children was highest in Uttar Pradesh (12·4 million [95% UI 2·1-45·0]), Bihar (7·3 million [1·3-26·1]), and Madhya Pradesh (4·6 million [0·7-17·0]). Between 2000 and 2015, the greatest reduction in pneumonia cases was observed in Kerala (82% reduction). In 2015, pneumonia incidence was greater than 500 cases per 1000 children in two states: Uttar Pradesh (565 cases per 1000 children [95% UI 94-2047]) and Madhya Pradesh (563 cases per 1000 children [88-2084]).

INTERPRETATION

The estimated number of pneumonia and severe pneumonia cases among children younger than 5 years in India decreased between 2000 and 2015. Improvements in socioeconomic indicators and specific government initiatives are likely to have contributed to declines in the prevalence of pneumonia risk factors in many states. However, pneumonia incidence in many states remains high. The introduction of new vaccines that target pneumonia pathogens and reduce risk factors will help further reduce the burden of pneumonia in the country.

FUNDING

Bill & Melinda Gates Foundation.

Factors impacting self-pay pediatric vaccine utilization in China: a large-scale maternal survey

OBJECTIVES

Utilization of self-pay vaccines worldwide is very low, especially in China; the reasons for this are unclear. We aimed to identify factors that impact the decision among Chinese mothers to utilize self-pay vaccines for their children.

METHODS

Mothers who were hospitalized at two hospitals in Zhanjiang City and who agreed to participate by completing the required questionnaire were eligible for this study.

RESULTS

In total, 7518 respondents (n = 7592) completed the questionnaire and were included in this survey. The self-pay option was largely elected by mothers with one child, compared with those who had two or more children. Similarly, utilization by workers at government agencies and organizations was higher than that among factory workers or unemployed respondents. Mothers with a college degree or above had higher utilization than those with a high school level education or lower. The main issues affecting maternal decisions to utilize self-pay pediatric vaccines were safety, the protective effect, and the high cost.

CONCLUSION

Mothers with higher socioeconomic status were more inclined to self-pay for pediatric vaccines. Steps taken to enhance public awareness about the safety and protective benefits of self-pay vaccines, as well as lowering their cost will likely encourage broader utilization of these vaccines.

Common Genetic Variations Associated with the Persistence of Immunity following Childhood Immunization

Vaccines have revolutionized public health, preventing millions of deaths each year, particularly in childhood. Yet, there is considerable variability in the magnitude and persistence of vaccine-induced immunity. Maintenance of specific antibody is essential for continuity of vaccine-induced serological protection. We conducted a genome-wide association study into the persistence of immunity to three childhood vaccines: capsular group C meningococcal (MenC), Haemophilus influenzae type b, and tetanus toxoid (TT) vaccines. We detail associations between variants in a locus containing a family of signal-regulatory proteins and the persistence MenC immunity. We postulate a regulatory role for the lead SNP, with supporting epigenetic and expression quantitative trait loci data. Furthermore, we define associations between SNPs in the human leukocyte antigen (HLA) locus and the persistence of TT-specific immunity. Moreover, we describe four classical HLA alleles, HLA DRB1^∗0301, HLA DQB1^∗0201, HLA DQB1^∗0602, and HLA DRB1^∗1501, associated with TT-specific immunity, independent of the lead SNP association.

National, regional, and state-level burden of Streptococcus pneumoniae and Haemophilus influenzae type b disease in children in India: modelled estimates for 2000-15

Background

India accounts for a disproportionate burden of global childhood illnesses. To inform policies and measure progress towards achieving child health targets, we estimated the annual national and state-specific childhood mortality and morbidity attributable to Streptococcus pneumoniae and Haemophilus influenzae type b (Hib) between 2000 and 2015.

Methods

In this modelling study, we used vaccine clinical trial data to estimate the proportion of pneumonia deaths attributable to pneumococcus and Hib. The proportion of meningitis deaths attributable to each pathogen was derived from pathogen-specific meningitis case fatality and bacterial meningitis case data from surveillance studies. We applied these proportions to modelled state-specific pneumonia and meningitis deaths from 2000 to 2015 prepared by the WHO Maternal and Child Epidemiology Estimation collaboration (WHO/MCEE) on the basis of verbal autopsy studies from India. The burden of clinical and severe pneumonia cases attributable to pneumococcus and Hib was ascertained with vaccine clinical trial data and state-specific all-cause pneumonia case estimates prepared by WHO/MCEE by use of risk factor prevalence data from India. Pathogen-specific meningitis cases were derived from state-level modelled pathogen-specific meningitis deaths and state-level meningitis case fatality estimates. Pneumococcal and Hib morbidity due to non-pneumonia, non-meningitis (NPNM) invasive syndromes were derived by applying the ratio of pathogen-specific NPNM cases to pathogen-specific meningitis cases to the state-level pathogen-specific meningitis cases. Mortality due to pathogen-specific NPNM was calculated with the ratio of pneumococcal and Hib meningitis case fatality to pneumococcal and Hib meningitis NPNM case fatality. Census data from India provided the population at risk.

Findings

Between 2000 and 2015, estimates of pneumococcal deaths in Indian children aged 1–59 months fell from 166 000 (uncertainty range [UR] 110 000–198 000) to 68 700 (44 600–86 000), while Hib deaths fell from 82 600 (52 300–112 000) to 15 600 (9800–21 500), representing a 58% (UR 22–78) decline in pneumococcal deaths and an 81% (59–91) decline in Hib deaths. In 2015, national mortality rates in children aged 1–59 months were 56 (UR 37–71) per 100 000 for pneumococcal infection and 13 (UR 8–18) per 100 000 for Hib. Uttar Pradesh (18 900 [UR 12 300–23 600]) and Bihar (8600 [5600–10 700]) had the highest numbers of pneumococcal deaths in 2015. Uttar Pradesh (9300 [UR 5900–12 700]) and Odisha (1100 [700–1500]) had the highest numbers of Hib deaths in 2015. Less conservative assumptions related to the proportion of pneumonia deaths attributable to pneumococcus indicate that as many as 118 000 (UR 69 000–140 000) total pneumococcal deaths could have occurred in 2015 in India.

Interpretation

Pneumococcal and Hib mortality have declined in children aged 1–59 months in India since 2000, even before nationwide implementation of conjugate vaccines. Introduction of the Hib vaccine in several states corresponded with a more rapid reduction in morbidity and mortality associated with Hib infection. Rapid scale-up and widespread use of the pneumococcal conjugate vaccine and sustained use of the Hib vaccine could help accelerate achievement of child survival targets in India.

Funding

Bill & Melinda Gates Foundation.

Infant antibody levels following 10-valent pneumococcal-protein D conjugate and DTaP-Hib vaccinations in the first year of life after maternal Tdap vaccination: An open-label, parallel, randomised controlled trial

BACKGROUND

Maternal antibody levels after Tdap vaccination during pregnancy may affect infant primary antibody responses to pertussis, Tetanus toxoid (TT), Diphtheria toxoid (DT) vaccinations and pneumococcal vaccines with diphtheria toxin mutants like CRM197 as carrier protein.

METHODS

Mothers were recruited in an open label randomised parallel controlled trial in 2014-2016 through midwifes. They received Tdap [Boostrix] at 30-32 weeks of pregnancy (n = 58) or within 48 h after delivery (n = 60). Infants received DTaP-IPV-Hib-HepB [Infanrix Hexa] and 10-valent protein D conjugated pneumococcal conjugate vaccine (PHiD-CV10 [Synflorix]) at age 3, 5 and 11 months. We now report on infant specific IgG levels towards DT, TT, Haemophilus influenzae type b polyribosylribitol phosphate (Hib PRP) and PHiD-CV10 before and after primary- and booster vaccination as secondary study endpoints; pertussis antibodies were the primary endpoint of the study. This trial is registered in clinicaltrialsregister.eu (EudraCT 2012-004006-9) and trialregister.nl (NTR number NTR4314).

FINDINGS

Post primary vaccinations, antibody levels to DT, but not TT, were significantly lower after Tdap vaccination during pregnancy compared to controls (GMC ratio 0.4, 95% CI 0.3-0.6 and 0.9, 95% CI 0.6-1.2, respectively). Antibodies to serotype 19F were significantly lower in the maternal Tdap group, whereas there were no differences in antibody levels to Hib PRP and the other 9 pneumococcal serotypes. Post booster vaccinations, no significant differences were observed, except for DT.

INTERPRETATION

Maternal Tdap vaccination results in significant interference with infants responses not only to DT but also to conjugated pneumococcal vaccines containing DT mutants as carrier proteins. These interactions after maternal Tdap vaccination need to be taken into account when designing infants' national immunization schedules and choice of vaccines.

FUNDING

The Dutch Ministry of Health, Welfare and Sport.