Haemophilus Influenzae Protein Research Articles

Hearing loss in Australian First Nations children at 6-monthly assessments from age 12 to 36 months: Secondary outcomes from randomised controlled trials of novel pneumococcal conjugate vaccine schedules.

In Australian remote communities, First Nations children with otitis media (OM)-related hearing loss are disproportionately at risk of developmental delay and poor school performance, compared to those with normal hearing. Our objective was to compare OM-related hearing loss in children randomised to one of 2 pneumococcal conjugate vaccine (PCV) formulations. In 2 sequential parallel, open-label, randomised controlled trials (the PREVIX trials), eligible infants were first allocated 1:1:1 at age 28 to 38 days to standard or mixed PCV schedules, then at age 12 months to PCV13 (13-valent pneumococcal conjugate vaccine, +P) or PHiD-CV10 (10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine, +S) (1:1). Here, we report prevalence and level of hearing loss outcomes in the +P and +S groups at 6-monthly scheduled assessments from age 12 to 36 months. From March 2013 to September 2018, 261 infants were enrolled and 461 hearing assessments were performed. Prevalence of hearing loss was 78% (25/32) in the +P group and 71% (20/28) in the +S group at baseline, declining to 52% (28/54) in the +P groups and 56% (33/59) in the +S group at age 36 months. At primary endpoint age 18 months, prevalence of moderate (disabling) hearing loss was 21% (9/42) in the +P group and 41% (20/49) in the +S group (difference -19%; (95% confidence interval (CI) [-38, -1], p = 0.07) and prevalence of no hearing loss was 36% (15/42) in the +P group and 16% (8/49) in the +S group (difference 19%; (95% CI [2, 37], p = 0.05). At subsequent time points, prevalence of moderate hearing loss remained lower in the +P group: differences -3%; (95% CI [-23, 18], p = 1.00 at age 24 months), -12%; (95% CI [-30, 6], p = 0.29 at age 30 months), and -9%; (95% CI [-23, 5], p = 0.25 at age 36 months). A major limitation was the small sample size, hence low power to reach statistical significance, thereby reducing confidence in the effect size. In this study, we observed a high prevalence and persistence of moderate (disabling) hearing loss throughout early childhood. We found a lower prevalence of moderate hearing loss and correspondingly higher prevalence of no hearing loss in the +P group, which may have substantial benefits for high-risk children, their families, and society, but warrant further investigation. ClinicalTrials.gov NCT01735084 and NCT01174849.

Global, Regional, and National Burdens of Otitis Media From 1990 to 2019: A Population Based Study.

Otitis media is one of the most important causes of hearing loss at an early age. Effective vaccination with the routine 7-valent pneumococcal conjugate vaccine (PCV-7) was introduced in 2000. It has been gradually replaced by the pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine or the higher-valent 13-valent PCV (PCV-13) since 2010. Data on the change in otitis media burden in recent years are sparse at the global, regional, and national levels. The Global Burden of Disease 2019 study was used to evaluate the prevalence, incidence, mortality, disability-adjusted life year (DALY) rates, and the average annual percentage changes (AAPCs) in otitis media in geographic populations worldwide from 1990 to 2019. These global trends were further analyzed by subgroup (age, sex, and sociodemographic index [SDI]). Globally, the all-age rate of prevalence (AAPC = -0.7, 95% confidence interval [CI] = -0.7 to -0.8), DALYs (AAPC = -1.0, 95% CI = -1.1 to -1.0), and mortality (AAPC = -6.8, 95% CI = -7.3 to -6.4) from otitis media decreased constantly between 1990 and 2019. The all-age rate of incidence decreased sharply between 2000 and 2009 with an AAPC of -1.2 (95% CI = -1.4 to -0.9) and continued the downward trend between 2010 and 2019 (AAPC = -0.2, 95% CI = -0.3 to -0.1). In 2019, children aged 1 to 4 years old had the highest incidence at 29,127.3 per 100,000 population, while young adults under 30 years old accounted for 91.3% of the incident cases. Individuals living in middle-SDI countries had the largest increase in the incidence of otitis media, with an AAPC of 0.3 (95% CI = 0.3 to 0.3) between 1990 and 2019. The incidence and DALYs from otitis media decreased with increasing SDI. Regionally, the largest increase in incidence was observed in high-income Asia Pacific, Eastern Europe, and Western Sub-Saharan Africa between 1990 and 2019. Nationally, the largest increase in the incidence of otitis media was observed in the Republic of Korea, with an AAPC of 0.8 (95% CI = 0.6 to 1.1) in the same time period. There have been successful previous endeavors to reduce DALYs and mortality attributed to otitis media on a global scale. The worldwide incidence of otitis media experienced a sharp decline following the introduction of PCV-7 in 2000, and this downward trend persisted in subsequent years with the adoption of PCV-13/pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine. Continual epidemiological surveillance of otitis media's global trends, pathogen distribution, and resistance patterns remains imperative.

Otitis media at 6-monthly assessments of Australian First Nations children between ages 12–36 months: Findings from two randomised controlled trials of combined pneumococcal conjugate vaccines

ObjectivesIn remote communities of northern Australia, First Nations children with hearing loss are disproportionately at risk of poor school readiness and performance compared to their peers with no hearing loss. The aim of this trial is to prevent early childhood persisting otitis media (OM), associated hearing loss and developmental delay. To achieve this, we designed a mixed pneumococcal conjugate vaccine (PCV) schedule that could maximise immunogenicity and thereby prevent bacterial otitis media (OM) and a trajectory of educational and social disadvantage. MethodsIn two sequential parallel, open-label, randomised controlled trials, eligible infants were first allocated 1:1:1 to standard or mixed PCV primary schedules at age 28–38 days, then at age 12 months to a booster dose (1:1) of 13-valent PCV, PCV13 (Prevenar13®, +P), or 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugated vaccine, PHiD-CV10 (Synflorix®, +S). Here we report findings of standardised ear assessments conducted six-monthly from age 12–36 months, by booster dose. ResultsFrom March 2013 to September 2018, 261 children were allocated to booster + P (n = 131) or + S (n = 130). There were no significant differences in prevalence of any OM diagnosis by booster dose or when stratified by primary schedule. We found high, almost identical prevalence of OM in both boost groups at each age (for example 88% of 129 and 91% of 128 children seen, respectively, at primary endpoint age 18 months, difference −3% [95% Confidence Interval −11, 5]). At each age prevalence of bilateral OM was 52%–78%, and tympanic membrane perforation was 10%–18%. ConclusionDespite optimal pneumococcal immunisation, the high prevalence of OM persists throughout early childhood. Novel approaches to OM prevention are needed, along with improved early identification strategies and evaluation of expanded valency PCVs.

Expression conditions and characterization of a novelly constructed lipoprotein intended as a vaccine to prevent human Haemophilus influenzae infections

Bacterial lipoproteins are structurally divided into two groups, based on their lipid moieties: diacylated (present in Gram-positive bacteria) and triacylated (present in some Gram-positive and most Gram-negative bacteria). Diacylated and triacylated lipid moieties differ by a single amide-linked fatty acid chain. Lipoproteins induce host innate immune responses by the mammalian Toll-like receptor 2 (TLR2). In this study, we added a lipid moiety to recombinant OMP26, a native nonlipidated (NL) membrane protein of Haemophilus influenzae, and characterized it extensively under different expression conditions using flow cytometry, LC/MS, and MALDI-TOF. We also investigated the ability of NL and lipidated (L) OMP26 to induce invitro stimulation of HEK Blue-hTLR2-TR1 and hTLR-TLR6 cells. Our L-OMP26 was predominantly expressed in diacylated form, so we employed an additional gene copy of apolipoprotein N-acetyltransferase enzyme (Lnt)-rich Escherichia coli strain that further acylates the diacyl lipoproteins to enhance the production of triacylated L-OMP26. The diacyl and triacyl versions of L-OMP26, intended as a vaccine for use in humans, were characterized and evaluated as protein vaccine components in a mouse model. We found that the diacyl and triacyl L-OMP26 protein formulations differed markedly in their immune-stimulatory activity, with diacylated L-OMP26 stimulating higher adaptive immune responses compared with triacylated L-OMP26 and both stimulating higher adaptive immune response compared to NL-OMP26. We also constructed and characterized an L-OMP26φNL-P6 fusion protein, where NL-P6 protein (a commonly studied H.influenzae vaccine candidate) was recombinantly fused to L-OMP26. We observed a similar pattern of lipidation (predominantly diacylated) in the L-OMP26φNL-P6 fusion protein.

Evaluation of the direct and indirect impact on pneumonia hospitalization after almost a decade of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine in Brazil

Evaluation of the direct and indirect impact on pneumonia hospitalization after almost a decade of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine in Brazil

EE166 Cost-Effectiveness of the Pneumococcal Conjugate Vaccine 10 Versus 13 on Pneumococcal Disease in Children in Sweden

Streptococcus pneumoniae (pneumococcus) can cause invasive pneumococcal diseases (IPD) such as meningitis and non-invasive disease, including pneumonia and acute otitis media (AOM). Since 2009, the paediatric immunization program in Sweden included the pneumococcal conjugate vaccine (PCV13) and the pneumococcal non-typeable Haemophilus influenzae (NTHi) protein D-conjugate vaccine (PHiD-CV), leading to an overall decrease in pneumococcus-related disease and AOM. The aim of this study is to assess the cost-effectiveness of PHiD-CV compared to PCV-13 in children from a societal perspective in Sweden.

Pneumonia hospitalizations of children aged

ABSTRACT As infection with Streptococcus pneumoniae is an important cause of pneumonia in children, the World Health Organization recommends childhood pneumococcal conjugate vaccines (PCVs). In January 2017, PCV universal mass vaccination (UMV) was introduced in Poland for children aged <2 years. The objective of this study was to estimate and describe the trends in the incidences of various types of pneumonia hospitalizations in Poland before (2013–2016) and after (2017–2018) introduction of the UMV program. The study was conducted at the regional hospitals of Opole and Bialystok and included all hospitalized children aged <2 years with a primary or secondary diagnosis of pneumonia in their electronic medical records. Pneumonia diagnoses were identified based on International Classification of Diseases 10th revision (ICD-10) codes for bacterial, viral, and other/unknown-cause pneumonias. The effect of the implementation of PCV UMV was modeled via an inferential multivariate model. Among 4,168 children included in the study, 64.3% were admitted before PCV UMV. The number of radiograph-confirmed likely bacterial pneumonia cases varied between 55 and 176 cases per 100,000 person-years, and no trend was observed over time. However, inferential modeling showed statistically significant decreasing trends in the incidence rates of bacterial-coded pneumonia (28.48%), viral-coded pneumonia (35.36%), all-cause pneumonia (24.60%), and radiograph-confirmed likely non-bacterial pneumonia (24.98%) among children eligible for UMV. This might be the first indication of the impact of the PCV UMV program in Poland.

Vaccine target and carrier molecule nontypeable Haemophilus influenzae protein D dimerizes like the close Escherichia coli GlpQ homolog but unlike other known homolog dimers.

We have determined the 1.8Å X-ray crystal structure of nonlipidated (i.e., N-terminally truncated) nontypeable Haemophilus influenzae (NTHi; H. influenzae) protein D. Protein D exists on outer membranes of H. influenzae strains and acts as a virulence factor that helps invade human cells. Protein D is a proven successful antigen in animal models to treat obstructive pulmonary disease (COPD) and otitis media (OM), and when conjugated to polysaccharides also has been used as a carrier molecule for human vaccines, for example in GlaxoSmithKline Synflorix™. NTHi protein D shares high sequence and structural identify to the Escherichia coli (E. coli) glpQ gene product (GlpQ). E. coli GlpQ is a glycerophosphodiester phosphodiesterase (GDPD) with a known dimeric structure in the Protein Structural Database, albeit without an associated publication. We show here that both structures exhibit similar homodimer organization despite slightly different crystal lattices. Additionally, we have observed both the presence of weak dimerization and the lack of dimerization in solution during size exclusion chromatography (SEC) experiments yet have distinctly observed dimerization in native mass spectrometry analyses. Comparison of NTHi protein D and E. coli GlpQ with other homologous homodimers and monomers shows that the E. coli and NTHi homodimer interfaces are distinct. Despite this distinction, NTHi protein D and E. coli GlpQ possess a triose-phosphate isomerase (TIM) barrel domain seen in many of the other homologs. The active site of NTHi protein D is located near the center of this TIM barrel. A putative glycerol moiety was modeled in two different conformations (occupancies) in the active site of our NTHi protein D structure and we compared this to ligands modeled in homologous structures. Our structural analysis should aid in future efforts to determine structures of protein D bound to substrates, analog intermediates, and products, to fully appreciate this reaction scheme and aiding in future inhibitor design.

Examination of phase-variable haemoglobin-haptoglobin binding proteins in non-typeable Haemophilus influenzae reveals a diverse distribution of multiple variants.

Non-typeable Haemophilus influenzae (NTHi) is a major human pathogen for which there is no globally licensed vaccine. NTHi has a strict growth requirement for iron and encodes several systems to scavenge elemental iron and heme from the host. An effective NTHi vaccine would target conserved, essential surface factors, such as those involved in iron acquisition. Haemoglobin–haptoglobin binding proteins (Hgps) are iron-uptake proteins localized on the outer-membrane of NTHi. If the Hgps are to be included as components of a rationally designed subunit vaccine against NTHi, it is important to understand their prevalence and diversity. Following analysis of all available Hgp sequences, we propose a standardized grouping method for Hgps, and demonstrate increased diversity of these proteins than previously determined. This analysis demonstrated that genes encoding variants HgpB and HgpC are present in all strains examined, and almost 40% of strains had a duplicate, nonidentical hgpB gene. Hgps are also phase-variably expressed; the encoding genes contain a CCAA(n) simple DNA sequence repeat tract, resulting in biphasic ON–OFF switching of expression. Examination of the ON–OFF state of hgpB and hgpC genes in a collection of invasive NTHi isolates demonstrated that 58% of isolates had at least one of hgpB or hgpC expressed (ON). Varying expression of a diverse repertoire of hgp genes would provide strains a method of evading an immune response while maintaining the ability to acquire iron via heme. Structural analysis of Hgps also revealed high sequence variability at the sites predicted to be surface exposed, demonstrating a further mechanism to evade the immune system—through varying the surface, immune-exposed regions of the membrane anchored protein. This information will direct and inform the choice of candidates to include in a vaccine against NTHi.

Immunogenicity, otitis media, hearing impairment, and nasopharyngeal carriage 6-months after 13-valent or ten-valent booster pneumococcal conjugate vaccines, stratified by mixed priming schedules: PREVIX_COMBO and PREVIX_BOOST randomised controlled trials

Australian First Nations children are at very high risk of early, recurrent, and persistent bacterial otitis media and respiratory tract infection. With the PREVIX randomised controlled trials, we aimed to evaluate the immunogenicity of novel pneumococcal conjugate vaccine (PCV) schedules. PREVIX_BOOST was a parallel, open-label, outcome-assessor-blinded, randomised controlled trial. Aboriginal children living in remote communities of the Northern Territory of Australia were eligible if they had previously completed the three-arm PREVIX_COMBO randomised controlled trial of the following vaccine schedules: three doses of a 13-valent PCV (PCV13; PPP) or a ten-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10; SSS) given at 2, 4, and 6 months, or SSS given at 1, 2, and 4 months followed by PCV13 at 6 months (SSSP). At age 12 months, eligible children were randomly assigned by a computer-generated random sequence (1:1, stratified by primary group allocation) to receive either a PCV13 booster or a PHiD-CV10 booster. Analyses used intention-to-treat principles. Co-primary outcomes were immunogenicity against protein D and serotypes 3, 6A, and 19A. Immunogenicity measures were geometric mean concentrations (GMC) and proportion of children with IgG concentrations of 0·35 μg/mL or higher (threshold for invasive pneumococcal disease), and GMCs and proportion of children with antibody levels of 100 EU/mL or higher against protein D. Standardised assessments of otitis media, hearing impairment, nasopharyngeal carriage, and developmental outcomes are reported. These trials are registered with ClinicalTrials.gov (NCT01735084 and NCT01174849). Between April 10, 2013, and Sept 4, 2018, 261 children were randomly allocated to receive a PCV13 booster (n=131) or PHiD-CV10 booster (n=130). Adequate serum samples for pneumococcal serology were obtained from 127 (95%) children in the PCV13 booster group and 126 (97%) in the PHiD-CV10 booster group; for protein D, adequate samples were obtained from 126 (96%) children in the PCV13 booster group and 123 (95%) in the PHiD-CV10 booster group. The proportions of children with IgG concentrations above standard thresholds in PCV13 booster versus PHiD-CV10 booster groups were the following: 71 (56%) of 126 versus 81 (66%) of 123 against protein D (difference 10%, 95% CI -2 to 22), 85 (67%) of 127 versus 59 (47%) of 126 against serotype 3 (-20%, -32 to -8), 119 (94%) of 127 versus 91 (72%) of 126 against serotype 6A (-22%, -31 to -13), and 116 (91%) of 127 versus 108 (86%) of 126 against serotype 19A (-5%, -13 to 3). Infant PCV13 priming mitigated differences between PCV13 and PHiD-CV10 boosters. In both groups, we observed a high prevalence of otitis media (about 90%), hearing impairment (about 75%), nasopharyngeal carriage of pneumococcus (about 66%), and non-typeable H influenzae (about 57%). Of 66 serious adverse events, none were vaccine related. Low antibody concentrations 6 months post-booster might indicate increased risk of pneumococcal infection. The preferred booster was PCV13 if priming did not have PCV13, otherwise either PCV13 or PHiD-CV10 boosters provided similar immunogenicity. Mixed schedules offer flexibility to regional priorities. Non-PCV13 serotypes and non-typeable H influenzae continue to cause substantial disease and disability in Australian First Nation's children. National Health and Medical Research Council (NHMRC).

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

ABSTRACT Background In response to the substantial clinical and economic burden of diseases caused by Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) in Tunisia, the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) was recently introduced into the national immunization program. However, there has yet to be a full-scale health economic analysis comparing currently available pneumococcal conjugate vaccines (PCVs) in Tunisia. Methods A Markov model that simulated the disease processes of invasive pneumococcal disease (IPD), pneumonia, and acute otitis media (AOM) over a newborn cohort lifetime was used to evaluate the cost-effectiveness/utility of PHiD-CV and the 13-valent pneumococcal conjugate vaccine (PCV13) from payer’s perspective, using 3% discounting. Vaccine effects were considered for up to 9 years of age. Results Vaccination with PHiD-CV or PCV13 was estimated to avert approximately 700 cases of IPD (200 meningitis, 500 bacteremia), and around 5,000 cases of all-cause pneumonia. However, PHiD-CV vaccination was estimated to avert around 4,000 additional AOM cases (18,000) versus PCV13 (14,000). Both PCVs were demonstrated to be cost-effective interventions, but PHiD-CV was estimated to generate additional cost savings of almost $1 million US dollars (USD) with similar levels of clinical benefits. An additional scenario which incorporated serotype-specific vaccine efficacy found no significant change in overall results. Conclusion PCVs are a cost-effective strategy to relieve the burden associated with diseases caused by S. pneumoniae and NTHi in Tunisia. PHiD-CV is more cost-effective than PCV13, generating similar health benefits, at a reduced net cost of almost $1 million USD per vaccinated cohort.

Cost-effectiveness of introducing infant vaccination against pneumococcal disease in Poland – comparison of non-typeable Haemophilus influenzae protein D (PHiD-CV) and 13-valent (PCV-13) pneumococcal conjugate vaccines

Background: Streptococcus pneumoniae can cause invasive pneumococcal diseases (IPD), pneumonia and acute otitis media (AOM), a common childhood infection that may require antibiotics. There were 3,236 IPD cases detected in Poland between 2006-2016, with incidence peaks among infants and the elderly. The case-fatality rate in 2016 was 6.7% among infants and 49.3% among the elderly. Since 2009, two infant pneumococcal conjugate vaccines are available in Poland (the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine [PHiD-CV], and the 13-valent pneumococcal conjugate vaccine [PCV-13]). The objective of this study was to assess the cost-effectiveness of routine PHiD-CV versus no vaccination and versus PCV-13. Methods: A previously published Markov cohort model was adapted for Poland to compare PHiD-CV to no vaccination and PCV-13 from the public payer perspective, regarding lifetime direct costs and quality-adjusted life years (QALYs) associated with morbidity and mortality due to IPD, pneumonia and AOM. PHiD-CV and PCV-13 were assumed to have the same efficacy for their ten common vaccine serotypes, and PHiD-CV was assumed to have conservative cross-protection effectiveness against serotypes 6A and 19A, and to be more protective against AOM due to its effectiveness against non-typeable Haemophilus influenzae. Scenario analyses assessed outcomes when vaccine price parity was assumed, when the effectiveness of PHiD-CV against serotype 19A IPD was omitted or increased, and, when the effectiveness of PCV-13 against serotype 3 IPD was varied. Results: PHiD-CV was a cost-effective option versus no vaccination, with a cost per QALY gained of Polish złoty (PLN) 94,933 (below the threshold for cost-effectiveness of PLN 134,514). Both vaccines had comparable health outcomes regarding IPD and pneumonia, while PHiD-CV achieved better health outcomes against AOM. PHiD-CV was the dominant strategy for Poland versus PCV-13 (resulting in a gain of 170 QALYs at a direct cost-saving of PLN 61.1 million). In scenario and sensitivity analyses, PHiD-CV remained the dominant strategy versus PCV-13. Conclusions: The introduction of PHiD-CV in the Polish national immunization programme is likely to reduce the disease burden due to IPD, pneumonia and AOM. It is a cost-effective strategy (versus no vaccination) and a cost-saving strategy (versus PCV-13) for the healthcare payer.

Etiology of pediatric lower respiratory tract infections in South Korea

ABSTRACT Lower respiratory tract infections (LRTIs) are an important cause of death and bacterial pneumonia is one of the most common causes of mortality in South Korea, but there is little data evaluating the epidemiology of pediatric LRTI in primary care clinics. We evaluated 1,497 pediatric LRTI cases in a primary care clinic over a two-year period from 2015 to 16 for clinical and radiological signs combined with PCR for pathogen detection. In addition, a 1,837 vaccine cohort in the clinic from 2014 to 16 was analyzed separately. Fifty-two percent of cases presented with fever and 15% of 1,423 X-rayed cases had positive pneumonia findings with the grade of fever correlating positively with the proportion of cases with positive chest findings. Bacterial identification was possible for 1,376 cases with Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae most common. A higher proportion of 13-valent pneumococcal conjugate vaccinated cases had positive pneumonia findings than 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) vaccinated cases, although similar proportions for each PCV had confirmed bacterial infections. PHiD-CV vaccinated cases with positive pneumonia findings had proportionally more single S. pneumoniae infections but less co-infections and less cases with H. influenzae infection. The proportions of confirmed bacterial infections in LRTI cases observed in this pediatric primary care setting in South Korea is very high, with co-infections most common. S. pneumoniae and H. influenzae are the most common as expected but this data also highlights M. pneumoniae as an additional important cause of LRTI in primary pediatric care in Korea.

Development of a bivalent conjugate vaccine candidate against rotaviral diarrhea and tuberculosis using polysaccharide from Mycobacterium tuberculosis conjugated to ΔVP8* protein from rotavirus

Conjugation of carbohydrate antigens with a carrier protein is a clinically proven strategy to overcome the poor immunogenicity of bacterial polysaccharide. In addition to its primary role, which is to help generate a T cell-mediate long-lasting immune response directed against the carbohydrate antigen, the carrier protein in a glycoconjugate vaccine can also play an important role as a protective antigen. Among carrier proteins currently used in licensed conjugate vaccines, non-typeable Haemophilus influenzae protein D has been used as an antigenically active carrier protein. Our previous studies also indicate that some carrier proteins provide B cell epitopes, along with T cell helper epitopes.Herein we investigated the dual role of truncated rotavirus spike protein ΔVP8* as a carrier and a protective antigen. Capsular polysaccharide lipoarabinomannan (LAM), purified from Mycobacterium tuberculosis (M.tb), was chemically conjugated with ΔVP8*. Mouse immunization experiments showed that the resultant conjugates elicited strong and specific immune responses against the polysaccharide antigen, and the responses were comparable to those induced by Diphtheria toxoid (DT)-based conjugates. The conjugate vaccine induced enhanced antibody titers and functional antibodies against ΔVP8* when compared to immunization with the unconjugated ΔVP8*. Thus, these results indicate that ΔVP8* can be a relevant carrier protein for glycoconjugate vaccine and the glycoconjugates consisting of ΔVP8* with LAM are effective bivalent vaccine candidates against rotavirus and tuberculosis.

Impact of pneumococcal conjugate vaccines on healthcare utilization and direct costs for otitis media in children ≤2 years of age in two Swedish regions

ABSTRACT In Sweden, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2009 and replaced by the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) or the 13-valent PCV (PCV13) from late 2009. We assessed the impact of PCVs on rates of antibiotic prescribing, tympanostomy tube placement (TTP), and healthcare resource utilization and direct costs of physician-diagnosed otitis media/acute otitis media (OM) in children ≤2 years of age living in Skåne (PCV7 then PHiD-CV) or Västra Götalandsregionen (VGR; PCV7 then PCV13). Retrospective cohort study using linked patient-level data from national and regional (Skåne and VGR) healthcare databases in Sweden from July 1, 2005, to December 31, 2013 (NCT02742753). Descriptive time-series analyses showed antibiotic prescriptions and TTP incidence declined after PHiD-CV/PCV13 introduction versus the pre-PCV period. The annualized mean frequencies of antibiotic use, primary care visits, outpatient visits, TTP and myringotomy procedures all decreased after PHiD-CV/PCV13 compared with pre-PCV cohorts. Annualized mean total OM-associated healthcare costs decreased in the PCV7 versus pre-PCV cohorts by 20.0% in Skåne and 10.2% in VGR, and further declined in the PHiD-CV and PCV13 cohorts (20.7% and 15.3%, respectively, relative to the PCV7 cohort), although the duration of PCV7 use differed between regions. Decreases in adjusted annualized cost ratios between cohorts per child susceptible to OM were statistically significant after PCV7 introduction and again with either PHiD-CV or PCV13 introduction in both regions. Following sequential PCV introduction, OM-related healthcare utilization and associated costs decreased in the study regions in Sweden. PLAIN LANGUAGE SUMMARY What is the context? Otitis media is one of the most frequent reasons for healthcare visits and antibiotic use among young children. Although it is considered as a mild illness, the overall economic burden is substantial due to its high frequency. Otitis media can be caused by different bacteria including Streptococcus pneumoniae, which is also responsible for pneumonia and meningitis. Pneumococcal conjugate vaccines Prevenar (Pfizer Inc.), Synflorix (GSK), and Prevenar 13 (Pfizer Inc.) protect against pneumococcal diseases and reduce its occurrence. However, it is not known how the routine use of these vaccines may affect otitis media-related healthcare resources and costs. What is new? In this study, we assessed trends in rates of healthcare utilization and associated costs due to otitis media in young children before (2005–2008) and after (2009–2013) use of pneumococcal conjugate vaccines. The study was conducted in two Swedish regions; one used Prevenar then Synflorix, while the other used Prevenar then Prevenar 13. We found that compared to the period before pneumococcal conjugate vaccine implementation, the post-pneumococcal conjugate vaccine period was associated with: A decrease in otitis media-related antibiotic prescriptions and surgical procedures in both regions. A decrease in the annual frequency of otitis media related antibiotic use, primary care and outpatient visits, and surgical procedures. A significant reduction in otitis media-related healthcare costs in both regions. What is the impact on current thinking? The use of pneumococcal conjugate vaccines effectively reduces healthcare utilization and resources associated with otitis media. This indirect effect on the reduction of otitis media burden provides further benefit to the implementation of pneumococcal vaccination.

Constrained Optimization for Pneumococcal Vaccination in Brazil

ObjectivesTo identify the most cost-efficient combination of pneumococcal vaccines in infants and aging adults for a 10-year period in Brazil. MethodsConstrained optimization (CO) prioritized 9 pneumococcal vaccine regimens according to their gain in quality-adjusted life-years (QALYs) and their related costs over a prespecified time horizon with defined constraints for 2 age groups, infants and aging adults. The analysis starts from the current universal infant vaccination of pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), 2 primary and 1 booster dose at 2, 4, and 12 months, respectively. Key constraints are the fixed annual vaccine budget increase and the relative return on investment (ROIR) per regimen, which must be > 1, the reference intervention being the current vaccination strategy in infants and the most cost-efficient one in aging adults. ResultsThe CO analysis including all the constraints indicates that over 10 years the maximum extra health gain is 126 194 QALYs for an extra budget of $974 million Brazilian reals (ROIR = 1.15). Results could be improved with a higher proportion of the at-risk population in aging adults, less herd effect, and better QALY scores. ConclusionThe study shows that with 4 constraints on budget, time horizon, vaccine coverage, and cost efficiency, a CO analysis could identify the most cost-efficient overall pneumococcal vaccination strategy for Brazil, allowing for limited vaccine budget increase while obtaining appropriate health gain.

Nasopharyngeal carriage of otitis media pathogens in infants receiving 10-valent non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10), 13-valent pneumococcal conjugate vaccine (PCV13) or a mixed primary schedule of both vaccines: A randomised controlled trial

BackgroundAboriginal children in Northern Australia have a high burden of otitis media, driven by early and persistent nasopharyngeal carriage of otopathogens, including non-typeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae (Spn). In this context, does a combined mixed primary series of Synflorix and Prevenar13 provide better protection against nasopharyngeal carriage of NTHi and Spn serotypes 3, 6A and 19A than either vaccine alone? MethodsAboriginal infants (n = 425) were randomised to receive Synflorix™ (S, PHiD-CV10) or Prevenar13™ (P, PCV13) at 2, 4 and 6 months (_SSS or _PPP, respectively), or a 4-dose early mixed primary series of PHiD-CV10 at 1, 2 and 4 months and PCV13 at 6 months of age (SSSP). Nasopharyngeal swabs were collected at 1, 2, 4, 6 and 7 months of age. Swabs of ear discharge were collected from tympanic membrane perforations. FindingsAt the primary endpoint at 7 months of age, the proportion of nasopharyngeal (Np) swabs positive for PCV13-only serotypes 3, 6A, or 19A was 0%, 0.8%, and 1.5% in the _PPP, _SSS, and SSSP groups respectively, and NTHi 55%, 52%, and 52% respectively, and no statistically significant vaccine group differences in other otopathogens at any age. The most common serotypes (in order) were 16F, 11A, 10A, 7B, 15A, 6C, 35B, 23B, 13, and 15B, accounting for 65% of carriage. Ear discharge swabs (n = 108) were culture positive for NTHi (52%), S. aureus (32%), and pneumococcus (20%). ConclusionsAboriginal infants experience nasopharyngeal colonisation and tympanic membrane perforations associated with NTHi, non-PCV13 pneumococcal serotypes and S. aureus in the first months of life. Nasopharyngeal carriage of pneumococcus or NTHi was not significantly reduced in the early 4-dose combined SSSP group compared to standard _PPP or _SSS schedules at any time point. Current pneumococcal conjugate vaccine formulations do not offer protection from early onset NTHi and pneumococcal colonisation in this high-risk population.

Otitis media outcomes of a combined 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine and 13-valent pneumococcal conjugate vaccine schedule at 1-2-4-6\u2009months: PREVIX_COMBO, a 3-arm randomised controlled trial

BackgroundAboriginal children living in Australian remote communities are at high risk of early and persistent otitis media, hearing loss, and social disadvantage. Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are the primary pathogens. We compared otitis media outcomes in infants randomised to either a combination of Synflorix™ (PHiD-CV10, with protein D of NTHi) and Prevenar13™ (PCV13, with 3, 6A, and 19A), with recommended schedules for each vaccine alone. We previously reported superior broader overall immunogenicity of the combination schedule at 7 months, and early superiority of PHiD-CV10 compared to PCV13 at 4 months.MethodsIn an open-label superiority trial, we randomised (1:1:1) Aboriginal infants at 28 to 38 days of age, to either Prevenar13™ (P) at 2–4-6 months (_PPP), Synflorix™ (S) at 2–4-6 months (_SSS), or Synflorix™ at 1–2-4 months plus Prevenar13™ at 6 months (SSSP). Ears were assessed using tympanometry at 1 and 2 months, combined with otoscopy at 4, 6, and 7 months. A worst ear diagnosis was made for each child visit according to a severity hierarchy of normal, otitis media with effusion (OME), acute otitis media without perforation (AOMwoP), AOM with perforation (AOMwiP), and chronic suppurative otitis media (CSOM).ResultsBetween September 2011 and September 2017, 425 infants were allocated to _PPP(143), _SSS(141) or SSSP(141). Ear assessments were successful in 96% scheduled visits. At 7 months prevalence of any OM was 91, 86, and 90% in the _PPP, _SSS, and SSSP groups, respectively. There were no significant differences in prevalence of any form of otitis media between vaccine groups at any age. Combined group prevalence of any OM was 43, 57, 82, 87, and 89% at 1, 2, 4, 6, and 7 months of age, respectively. Of 388 infants with ear assessments at 4, 6 and 7 months, 277 (71.4%) had OM that met criteria for specialist referral; rAOM, pOME, or CSOM.ConclusionsDespite superior broader overall immunogenicity of the combination schedule at 7 months, and early superiority of PHiD-CV10 compared to PCV13 at 4 months, there were no significant differences in prevalence of otitis media nor healthy ears throughout the first months of life.Trial registrationACTRN12610000544077 registered 06/07/2010 and ClinicalTrials.govNCT01174849 registered 04/08/2010.

Interchangeability, immunogenicity and safety of a combined 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (Synflorix) and 13-valent-PCV (Prevenar13) schedule at 1-2-4-6 months: PREVIX_COMBO, a 3-arm randomised controlled trial

BackgroundAboriginal children living in remote communities are at high risk of early and persistent otitis media. Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are primary pathogens. Vaccines with potential to prevent early OM have not been evaluated in this population. We compared immunogenicity (ELISA and opsonophagocytic activity) of a combination of Synflorix™ (PHiD-CV10, 10 serotypes and protein D of NTHi) and Prevenar13™ (PCV13, 10 serotypes plus 3, 6A, and 19A), with recommended schedules. MethodsThis open-label superiority trial randomised (1:1:1) Aboriginal infants at 28 to 38 days of age, to PCV13 (P) at 2–4-6 months (_PPP), PHiD-CV10 (S) at 2–4-6 months (_SSS), or PHiD-CV10 at 1–2–4 plus PCV13 at −6 months (SSSP). Primary outcomes (blinded) were immunogenicity against PCV13-only serotypes 3, 6A, 19A, and PHiD-CV10-only protein D at 7 months. Secondary outcomes include immunogenicity against all serotypes at 2, 4 and 7 months. FindingsBetween 2011 and 2017, 425 infants were allocated to _PPP(143), _SSS(141) or SSSP(141). An intention to treat approach including all available data was used. The SSSP group had superior immunogenicity against serotypes 3, 6A, and 19A compared to _SSS (OPA GMT ratios 8.1 to 59.5, p < 0.001), and against protein D compared to _PPP (GMC ratio 11.9 (95%CI 9.7 to 14.6)). Immune responses to protein D and 3, 6A, and 19A in SSSP were not significantly lower (i.e. no harm) than either _SSS or _PPP. For ten common serotypes responses at 2, 4 and 7 months were superior for SSSP (following 1-, 2-, and 4- doses) than _SSS and _PPP (following 0-, 1-, and 3- doses). At 4 months, _SSS was superior to _PPP. Reactogenicity and hospitalisations were rare and unrelated to the intervention. InterpretationFrom two months, the 1–2–4–6-month combined schedule (SSSP) was safe and significantly more immunogenic than 2–4–6-month schedules. The earlier responses may be beneficial in high-risk populations.

Profiling of Haemophilus influenzae strain R2866 with carbohydrate-based covalent probes.

We demonstrate the application of four covalent probes based on anomerically pure d-galactosamine and d-glucosamine scaffolds for the profiling of Haemophilus influenzae strain R2866. The probes have been used successfully for the labelling of target proteins not only in cell lysates, but also in intact cells. Differences in the labelling patterns between lysates and intact cells indicate that the probes can penetrate into the periplasm, but not the cytoplasm of H. influenzae. Analysis of selected target proteins by LC-MS/MS suggests predominant labelling of nucleotide-binding proteins, including several known antibacterial drug targets. Our protocols will aid the identification of molecular determinants of bacterial pathogenicity in Haemophilus influenzae and other bacterial pathogens.