Homologous and Heterologous Covid-19 Booster Vaccinations.

BACKGROUND: Although the three vaccines against coronavirus disease 2019 (Covid-19) that have received emergency use authorization in the United States are highly effective, breakthrough infections are occurring. Data are needed on the serial use of homologous boosters (same as the primary vaccine) and heterologous boosters (different from the primary vaccine) in fully vaccinated recipients. METHODS: In this phase 1-2, open-label clinical trial conducted at 10 sites in the United States, adults who had completed a Covid-19 vaccine regimen at least 12 weeks earlier and had no reported history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection received a booster injection with one of three vaccines: mRNA-1273 (Moderna) at a dose of 100 µg, Ad26.COV2.S (Johnson & Johnson-Janssen) at a dose of 5×1010 virus particles, or BNT162b2 (Pfizer-BioNTech) at a dose of 30 µg. The primary end points were safety, reactogenicity, and humoral immunogenicity on trial days 15 and 29. RESULTS: Of the 458 participants who were enrolled in the trial, 154 received mRNA-1273, 150 received Ad26.COV2.S, and 153 received BNT162b2 as booster vaccines; 1 participant did not receive the assigned vaccine. Reactogenicity was similar to that reported for the primary series. More than half the recipients reported having injection-site pain, malaise, headache, or myalgia. For all combinations, antibody neutralizing titers against a SARS-CoV-2 D614G pseudovirus increased by a factor of 4 to 73, and binding titers increased by a factor of 5 to 55. Homologous boosters increased neutralizing antibody titers by a factor of 4 to 20, whereas heterologous boosters increased titers by a factor of 6 to 73. Spike-specific T-cell responses increased in all but the homologous Ad26.COV2.S-boosted subgroup. CD8+ T-cell levels were more durable in the Ad26.COV2.S-primed recipients, and heterologous boosting with the Ad26.COV2.S vaccine substantially increased spike-specific CD8+ T cells in the mRNA vaccine recipients. CONCLUSIONS: Homologous and heterologous booster vaccines had an acceptable safety profile and were immunogenic in adults who had completed a primary Covid-19 vaccine regimen at least 12 weeks earlier. (Funded by the National Institute of Allergy and Infectious Diseases; DMID 21-0012 ClinicalTrials.gov number, NCT04889209.).

Tympanostomy Tubes or Medical Management for Recurrent Acute Otitis Media.

BACKGROUND: Official recommendations differ regarding tympanostomy-tube placement for children with recurrent acute otitis media. METHODS: We randomly assigned children 6 to 35 months of age who had had at least three episodes of acute otitis media within 6 months, or at least four episodes within 12 months with at least one episode within the preceding 6 months, to either undergo tympanostomy-tube placement or receive medical management involving episodic antimicrobial treatment. The primary outcome was the mean number of episodes of acute otitis media per child-year (rate) during a 2-year period. RESULTS: In our main, intention-to-treat analysis, the rate (±SE) of episodes of acute otitis media per child-year during a 2-year period was 1.48±0.08 in the tympanostomy-tube group and 1.56±0.08 in the medical-management group (P = 0.66). Because 10% of the children in the tympanostomy-tube group did not undergo tympanostomy-tube placement and 16% of the children in the medical-management group underwent tympanostomy-tube placement at parental request, we conducted a per-protocol analysis, which gave corresponding episode rates of 1.47±0.08 and 1.72±0.11, respectively. Among secondary outcomes in the main analysis, results were mixed. Favoring tympanostomy-tube placement were the time to a first episode of acute otitis media, various episode-related clinical findings, and the percentage of children meeting specified criteria for treatment failure. Favoring medical management was children's cumulative number of days with otorrhea. Outcomes that did not show substantial differences included the frequency distribution of episodes of acute otitis media, the percentage of episodes considered to be severe, and antimicrobial resistance among respiratory isolates. Trial-related adverse events were limited to those included among the secondary outcomes of the trial. CONCLUSIONS: Among children 6 to 35 months of age with recurrent acute otitis media, the rate of episodes of acute otitis media during a 2-year period was not significantly lower with tympanostomy-tube placement than with medical management. (Funded by the National Institute on Deafness and Other Communication Disorders and others; ClinicalTrials.gov number, NCT02567825.).

Efficacy of the mRNA-1273 SARS-CoV-2 Vaccine at Completion of Blinded Phase.

BACKGROUND: At interim analysis in a phase 3, observer-blinded, placebo-controlled clinical trial, the mRNA-1273 vaccine showed 94.1% efficacy in preventing coronavirus disease 2019 (Covid-19). After emergency use of the vaccine was authorized, the protocol was amended to include an open-label phase. Final analyses of efficacy and safety data from the blinded phase of the trial are reported. METHODS: We enrolled volunteers who were at high risk for Covid-19 or its complications; participants were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 µg) or placebo, 28 days apart, at 99 centers across the United States. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data cutoff date was March 26, 2021. RESULTS: The trial enrolled 30,415 participants; 15,209 were assigned to receive the mRNA-1273 vaccine, and 15,206 to receive placebo. More than 96% of participants received both injections, 2.3% had evidence of SARS-CoV-2 infection at baseline, and the median follow-up was 5.3 months in the blinded phase. Vaccine efficacy in preventing Covid-19 illness was 93.2% (95% confidence interval [CI], 91.0 to 94.8), with 55 confirmed cases in the mRNA-1273 group (9.6 per 1000 person-years; 95% CI, 7.2 to 12.5) and 744 in the placebo group (136.6 per 1000 person-years; 95% CI, 127.0 to 146.8). The efficacy in preventing severe disease was 98.2% (95% CI, 92.8 to 99.6), with 2 cases in the mRNA-1273 group and 106 in the placebo group, and the efficacy in preventing asymptomatic infection starting 14 days after the second injection was 63.0% (95% CI, 56.6 to 68.5), with 214 cases in the mRNA-1273 group and 498 in the placebo group. Vaccine efficacy was consistent across ethnic and racial groups, age groups, and participants with coexisting conditions. No safety concerns were identified. CONCLUSIONS: The mRNA-1273 vaccine continued to be efficacious in preventing Covid-19 illness and severe disease at more than 5 months, with an acceptable safety profile, and protection against asymptomatic infection was observed. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; COVE ClinicalTrials.gov number, NCT04470427.).

Differential Induction of Interferon Stimulated Genes by Cell-based Versus Egg-based Quadrivalent Influenza Vaccines in Children During the 2018-19 Season.

Cell-based quadrivalent inactivated influenza vaccine has been shown to have higher vaccine effectiveness than traditional egg-based quadrivalent inactivated influenza vaccine. This is observed despite similar levels of serum hemagglutinin antibodies induced by each vaccine. Here, we examine peripheral immune activation following egg-based or cell-based influenza vaccination in a clinical trial in children. Peripheral blood mononuclear cells were isolated and RNA sequenced from 81 study participants (41 Fluzone, egg-based and 40 Flucelvax, cell based) pre- and 7 days post- vaccination. Seroconversion was assessed by hemagglutinin inhibition assay. Differential gene expression was determined and pathway analysis was conducted. Cell-based influenza vaccine induced greater interferon stimulated and innate immune gene activation compared with egg-based influenza vaccine. Participants who seroconverted had increased interferon signaling activation versus those who did not seroconvert. These data suggest that cell-based influenza vaccine stimulates immune activation differently from egg-based influenza vaccine, shedding light on reported differences in vaccine effectiveness.

Genomic classification and antimicrobial resistance profiling of Streptococcus pneumoniae and Haemophilus influenza isolates associated with paediatric otitis media and upper respiratory infection.

Acute otitis media (AOM) is the most common childhood bacterial infectious disease requiring antimicrobial therapy. Most cases of AOM are caused by translocation of Streptococcus pneumoniae or Haemophilus influenzae from the nasopharynx to the middle ear during an upper respiratory tract infection (URI). Ongoing genomic surveillance of these pathogens is important for vaccine design and tracking of emerging variants, as well as for monitoring patterns of antibiotic resistance to inform treatment strategies and stewardship.In this work, we examined the ability of a genomics-based workflow to determine microbiological and clinically relevant information from cultured bacterial isolates obtained from patients with AOM or an URI. We performed whole genome sequencing (WGS) and analysis of 148 bacterial isolates cultured from the nasopharynx (N = 124, 94 AOM and 30 URI) and ear (N = 24, all AOM) of 101 children aged 6-35 months presenting with AOM or an URI. We then performed WGS-based sequence typing and antimicrobial resistance profiling of each strain and compared results to those obtained from traditional microbiological phenotyping.WGS of clinical isolates resulted in 71 S. pneumoniae genomes and 76 H. influenzae genomes. Multilocus sequencing typing (MSLT) identified 33 sequence types for S. pneumoniae and 19 predicted serotypes including the most frequent serotypes 35B and 3. Genome analysis predicted 30% of S. pneumoniae isolates to have complete or intermediate penicillin resistance. AMR predictions for S. pneumoniae isolates had strong agreement with clinical susceptibility testing results for beta-lactam and non beta-lactam antibiotics, with a mean sensitivity of 93% (86-100%) and a mean specificity of 98% (94-100%). MLST identified 29 H. influenzae sequence types. Genome analysis identified beta-lactamase genes in 30% of H. influenzae strains, which was 100% in agreement with clinical beta-lactamase testing. We also identified a divergent highly antibiotic-resistant strain of S. pneumoniae, and found its closest sequenced strains, also isolated from nasopharyngeal samples from over 15 years ago.Ultimately, our work provides the groundwork for clinical WGS-based workflows to aid in detection and analysis of H. influenzae and S. pneumoniae isolates.

Identifying Children Likely to Benefit From Antibiotics for Acute Sinusitis: A Randomized Clinical Trial.

Importance: The large overlap between symptoms of acute sinusitis and viral upper respiratory tract infection suggests that certain subgroups of children being diagnosed with acute sinusitis, and subsequently treated with antibiotics, derive little benefit from antibiotic use. Objective: To assess if antibiotic therapy could be appropriately withheld in prespecified subgroups. Design, Setting, and Participants: Randomized clinical trial including 515 children aged 2 to 11 years diagnosed with acute sinusitis based on clinical criteria. The trial was conducted between February 2016 and April 2022 at primary care offices affiliated with 6 US institutions and was designed to evaluate whether symptom burden differed in subgroups defined by nasopharyngeal Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis on bacterial culture and by the presence of colored nasal discharge. Interventions: Oral amoxicillin (90 mg/kg/d) and clavulanate (6.4 mg/kg/d) (n = 254) or placebo (n = 256) for 10 days. Main Outcomes and Measures: The primary outcome was symptom burden based on daily symptom scores on a validated scale (range, 0-40) during the 10 days after diagnosis. Secondary outcomes included treatment failure, adverse events including clinically significant diarrhea, and resource use by families. Results: Most of the 510 included children were aged 2 to 5 years (64%), male (54%), White (52%), and not Hispanic (89%). The mean symptom scores were significantly lower in children in the amoxicillin and clavulanate group (9.04 [95% CI, 8.71 to 9.37]) compared with those in the placebo group (10.60 [95% CI, 10.27 to 10.93]) (between-group difference, -1.69 [95% CI, -2.07 to -1.31]). The length of time to symptom resolution was significantly lower for children in the antibiotic group (7.0 days) than in the placebo group (9.0 days) (P = .003). Children without nasopharyngeal pathogens detected did not benefit from antibiotic treatment as much as those with pathogens detected; the between-group difference in mean symptom scores was -0.88 (95% CI, -1.63 to -0.12) in those without pathogens detected compared with -1.95 (95% CI, -2.40 to -1.51) in those with pathogens detected. Efficacy did not differ significantly according to whether colored nasal discharge was present (the between-group difference was -1.62 [95% CI, -2.09 to -1.16] for colored nasal discharge vs -1.70 [95% CI, -2.38 to -1.03] for clear nasal discharge; P = .52 for the interaction between treatment group and the presence of colored nasal discharge). Conclusions: In children with acute sinusitis, antibiotic treatment had minimal benefit for those without nasopharyngeal bacterial pathogens on presentation, and its effects did not depend on the color of nasal discharge. Testing for specific bacteria on presentation may represent a strategy to reduce antibiotic use in this condition. Trial Registration: ClinicalTrials.gov Identifier: NCT02554383.

Naturally Acquired Protection Against Upper Respiratory Symptoms Involving Group A Streptococcus in a Longitudinal Cohort Study.

BACKGROUND: Pharyngitis due to group A Streptococcus (GAS) represents a major cause of outpatient visits and antibiotic use in the United States. A leading vaccine candidate targets 30 of the > 200 emm types of GAS. We aimed to assess natural protection conferred by GAS against respiratory symptoms. METHODS: In a 5-year study among school-aged children in Pittsburgh, Pennsylvania, pharyngeal cultures were obtained from children at 2-week intervals, and active surveillance was conducted for respiratory illnesses. We assessed protection via the relative odds of previous detection of homologous strains (defined by field-inversion gel electrophoresis banding pattern), emm types, and emm clusters at visits where GAS was detected with symptoms, vs visits where GAS was detected without symptoms. We used a cluster bootstrap of children to adjust estimates for repeated sampling. RESULTS: At visits where previously detected GAS emm types were identified, we estimated 81.8% (95% confidence interval [CI], 67.1%-91.7%) protection against typical pharyngitis symptoms among children reacquiring the same strain, and 94.5% (95% CI, 83.5%-98.6%) protection among children acquiring a distinct strain. We estimated 77.1% (95% CI, 33.7%-96.3%) protection against typical symptoms among children acquiring partially heterologous emm types belonging to a previously detected emm cluster. Protection was evident after both symptomatic and asymptomatic detections of GAS. We did not identify strong evidence of protection against atypical respiratory symptoms. CONCLUSIONS: Within a 5-year longitudinal study, previous detection of GAS emm types was associated with protection against typical symptoms when homologous strains were subsequently detected. Naturally acquired protection against partially heterologous types suggests that emm type-based vaccines may have broader strain coverage than what has been previously assumed.

Biomarkers that differentiate false positive urinalyses from true urinary tract infection.

BACKGROUND: The specificity of the leukocyte esterase test (87%) is suboptimal. The objective of this study was to identify more specific screening tests that could reduce the number of children who unnecessarily receive antimicrobials to treat a presumed urinary tract infection (UTI). METHODS: Prospective cross-sectional study to compare inflammatory proteins in blood and urine samples collected at the time of a presumptive diagnosis of UTI. We also evaluated serum RNA expression in a subset. RESULTS: We enrolled 200 children; of these, 89 were later demonstrated not to have a UTI based on the results of the urine culture obtained. Urinary proteins that best discriminated between children with UTI and no UTI were involved in T cell response proliferation (IL-9, IL-2), chemoattractants (CXCL12, CXCL1, CXCL8), the cytokine/interferon pathway (IL-13, IL-2, INFγ), or involved in innate immunity (NGAL). The predictive power (as measured by the area under the curve) of a combination of four urinary markers (IL-2, IL-9, IL-8, and NGAL) was 0.94. Genes in the pathways related to inflammation were also upregulated in serum of children with UTI. CONCLUSIONS: Urinary proteins involved in the inflammatory response may be useful in identifying children with false positive results with current screening tests for UTI; this may reduce unnecessary treatment.

Corticosteroids to prevent kidney scarring in children with a febrile urinary tract infection: a randomized trial.

BACKGROUND: To evaluate the efficacy of adjuvant systemic corticosteroids in reducing kidney scarring. A previous study suggested that use of adjuvant systemic corticosteroids reduces kidney scarring in children radiologically confirmed to have extensive pyelonephritis. Efficacy of corticosteroids for children with febrile urinary tract infection (UTI) has not been studied. METHODS: Children aged 2 months to 6 years with their first febrile UTI were randomized to corticosteroids or placebo for 3 days (both arms received antimicrobial therapy); kidney scarring was assessed using 99mTc-dimercaptosuccinic acid kidney scan 5-24 months after the initial UTI. RESULTS: We randomized 546 children of which 385 had a UTI and 254 had outcome kidney scans (instead of the 320 planned). Rates of kidney scarring were 9.8% (12/123) and 16.8% (22/131) in the corticosteroid and placebo groups, respectively (p = 0.16), corresponding to an absolute risk reduction of 5.9% (95% confidence interval: - 2.2, 14.1). CONCLUSION: While children randomized to adjuvant corticosteroids tended to develop fewer kidney scars than children who were randomized to receive placebo, a statistically significant difference was not achieved. However, the study was limited by not reaching its intended sample size. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov , NCT01391793, Registered 7/12/2011 Graphical abstract.

Shortened Antimicrobial Treatment for Acute Otitis Media in Young Children.

BACKGROUND: Limiting the duration of antimicrobial treatment constitutes a potential strategy to reduce the risk of antimicrobial resistance among children with acute otitis media. METHODS: We assigned 520 children, 6 to 23 months of age, with acute otitis media to receive amoxicillin-clavulanate either for a standard duration of 10 days or for a reduced duration of 5 days followed by placebo for 5 days. We measured rates of clinical response (in a systematic fashion, on the basis of signs and symptomatic response), recurrence, and nasopharyngeal colonization, and we analyzed episode outcomes using a noninferiority approach. Symptom scores ranged from 0 to 14, with higher numbers indicating more severe symptoms. RESULTS: Children who were treated with amoxicillin-clavulanate for 5 days were more likely than those who were treated for 10 days to have clinical failure (77 of 229 children [34%] vs. 39 of 238 [16%]; difference, 17 percentage points [based on unrounded data]; 95% confidence interval, 9 to 25). The mean symptom scores over the period from day 6 to day 14 were 1.61 in the 5-day group and 1.34 in the 10-day group (P=0.07); the mean scores at the day-12-to-14 assessment were 1.89 versus 1.20 (P=0.001). The percentage of children whose symptom scores decreased more than 50% (indicating less severe symptoms) from baseline to the end of treatment was lower in the 5-day group than in the 10-day group (181 of 227 children [80%] vs. 211 of 233 [91%], P=0.003). We found no significant between-group differences in rates of recurrence, adverse events, or nasopharyngeal colonization with penicillin-nonsusceptible pathogens. Clinical-failure rates were greater among children who had been exposed to three or more children for 10 or more hours per week than among those with less exposure (P=0.02) and were also greater among children with infection in both ears than among those with infection in one ear (P<0.001). CONCLUSIONS: Among children 6 to 23 months of age with acute otitis media, reduced-duration antimicrobial treatment resulted in less favorable outcomes than standard-duration treatment; in addition, neither the rate of adverse events nor the rate of emergence of antimicrobial resistance was lower with the shorter regimen. (Funded by the National Institute of Allergy and Infectious Diseases and the National Center for Research Resources; ClinicalTrials.gov number, NCT01511107 .).

Host and Bacterial Markers that Differ in Children with Cystitis and Pyelonephritis.

OBJECTIVE: To determine whether treatment for urinary tract infections in children could be individualized using biomarkers for acute pyelonephritis. STUDY DESIGN: We enrolled 61 children with febrile urinary tract infections, collected blood and urine samples, and performed a renal scan within 2 weeks of diagnosis to identify those with pyelonephritis. Renal scans were interpreted centrally by 2 experts. We measured inflammatory proteins in blood and urine using LUMINEX or an enzyme-linked immunosorbent assay. We evaluated serum RNA expression using RNA sequencing in a subset of children. Finally, for children with Escherichia coli isolated from urine cultures, we performed a polymerase chain reaction for 4 previously identified virulence genes. RESULTS: Urinary markers that best differentiated pyelonephritis from cystitis included chemokine (C-X-C motif) ligand (CXCL)1, CXCL9, CXCL12, C-C motif chemokine ligand 2, INF γ, and IL-15. Serum procalcitonin was the best serum marker for pyelonephritis. Genes in the interferon-γ pathway were upregulated in serum of children with pyelonephritis. The presence of E coli virulence genes did not correlate with pyelonephritis. CONCLUSIONS: Immune response to pyelonephritis and cystitis differs quantitatively and qualitatively; this may be useful in differentiating these 2 conditions.

A method of processing nasopharyngeal swabs to enable multiple testing.

OBJECTIVE: To develop a method to perform multiple tests on a single nasopharyngeal (NP) swab. METHODS: We collected a NP swab on children aged 2-12 years with acute sinusitis and processed it for bacterial culture, viruses, cytokine expression, and 16S ribosomal RNA gene sequencing analysis. During the course of the study, we expand the scope of evaluation to include RNA-sequencing, which we accomplished by cutting the tip of the swab. RESULTS: Of the 174 children enrolled, 126 (72.4%) had a positive bacterial culture and 121 (69.5%) tested positive for a virus. Cytokine measurement, as judged by adequate levels of a housekeeping enzyme (glyceraldehyde 3-phosphate dehydrogenase), appeared successful. From the samples used for 16S ribosomal sequencing we recovered, on average, 16,000 sequences per sample, accounting for a total of 2646 operational taxonomic units across all samples sequenced. Samples used for RNA-sequencing had a mean RNA integrity number of 6.0. Cutting the tip of the swab did not affect the recovery yield for viruses or bacteria, nor did it affect species richness in microbiome analysis. CONCLUSION: We describe a minimally invasive sample collection protocol that allows for multiple diagnostic and research investigations in young children.

Reduced-Concentration Clavulanate for Young Children with Acute Otitis Media.

Amoxicillin-clavulanate (A/C) is currently the most effective oral antimicrobial in treating children with acute otitis media (AOM), but the standard dosage of 90 mg amoxicillin/6.4 mg clavulanate/kg of body weight/day commonly causes diarrhea. We examined whether an A/C formulation containing lower concentrations of clavulanate would result in less diarrhea while maintaining plasma levels of amoxicillin and clavulanate adequate to eradicate middle-ear pathogens and to achieve clinical success. We conducted an open-label study in children with AOM who were 6 to 23 months of age. In phase 1, we treated 40 children with a reduced-clavulanate A/C formulation providing 90 mg amoxicillin/3.2 mg clavulanate/kg/day for 10 days. In phase 2, we treated 72 children with the same formulation at a dosage of 80 mg amoxicillin/2.85 mg clavulanate/kg/day for 10 days. We compared the rates of protocol-defined diarrhea (PDD), diaper dermatitis, and AOM clinical response in these children with rates we had reported in children who received the standard A/C regimen, and we obtained plasma levels of amoxicillin and clavulanate at various time points. Outcomes in phase 1 children and in children who had received the standard regimen did not differ significantly. Rates of PDD in children receiving phase 2 and standard regimens were 17% and 26%, respectively (P = 0.10). The corresponding rates of diaper dermatitis were 21% and 33% (P = 0.04) and of AOM treatment failure were 12% and 16% (P = 0.44). Symptomatic responses did not differ significantly between regimens; both gave clavulanate levels sufficient to inhibit ß-lactamase activity. In young children with AOM, clavulanate dosages lower than those currently used may be associated with fewer side effects without reducing clinical efficacy. (This study has been registered at ClinicalTrials.gov under registration no. NCT02630992.).

A Cost-Utility Analysis of 5 Strategies for the Management of Acute Otitis Media in Children.

OBJECTIVE: To assess whether antimicrobial therapy in young children with acute otitis media reduces time to resolution of symptoms, overall symptom burden, and persistence of otoscopic evidence of infection. We used a cost-utility model to evaluate whether immediate antimicrobial treatment seems to be worthwhile, and if so, which antimicrobial agent is most cost effective. STUDY DESIGN: We compared the cost per quality-adjusted life-day of 5 treatment regimens in children younger than 2 years of age with acute otitis media: immediate amoxicillin/clavulanate, immediate amoxicillin, immediate cefdinir, watchful waiting, and delayed prescription (DP) for antibiotic. RESULTS: The 5 treatment regimens, listed in order from least effective to most effective were DP, watchful waiting, immediate cefdinir, immediate amoxicillin, and immediate amoxicillin/clavulanate. Listed in order from least costly to most costly, the regimens were DP, immediate amoxicillin, watchful waiting, immediate amoxicillin/clavulanate, and immediate cefdinir. The incremental cost-utility ratio of immediate amoxicillin compared with DP was $101.07 per quality-adjusted life-day gained. The incremental cost-utility ratio of immediate amoxicillin/clavulanate compared with amoxicillin was $2331.28 per quality-adjusted life-day gained. CONCLUSIONS: In children younger than 2 years of age with acute otitis media and no recent antibiotic exposure, immediate amoxicillin seems to be the most cost-effective initial treatment.

Cell-Mediated Immunity Against Antigenically Drifted Influenza A(H3N2) Viruses in Children During a Vaccine Mismatch Season.

BACKGROUND: Emergence of antigenically drifted influenza A(H3N2) viruses resulted in reduced vaccine effectiveness in all age groups during the 2014-2015 influenza season. In children, inactivated influenza vaccine (IIV) elicited neutralizing antibodies (Abs) against drifted strains at significantly lower levels than against the vaccine strain. Little is known about the cross-reactivity of cell-mediated immunity against drifted strains in children. METHODS: Children aged 3-17 years (n = 48) received IIV during the 2014-2015 influenza season. Peripheral blood mononuclear cells, collected before (on day 0) and after (on days 7 and 21) vaccination were evaluated for induction of cross-reactive plasmablasts, memory B cells, and cytokine-secreting CD4(+) and CD8(+) T cells against the vaccine and drifted A(H3N2) viruses by an enzyme-linked immunospot assay and flow cytometry. RESULTS: IIV increased frequencies of plasmablasts and memory B cells. The overall induction of the T-cell response was not significant. Both B-cell and T-cell responses showed significant cross-reactivity against A(H3N2) viruses. Age and preexisting immunity affected virus-specific plasmablast responses and fold-change of T-cell responses, respectively. The proportion of T-helper type 1-prone (ie, interferon γ- or tumor necrosis factor α-secreting) CD4(+) T cell responses also increased with age. CONCLUSIONS: In children aged 3-17 years, B- and T-cell responses following IIV receipt showed significant cross-reactivity against A(H3N2) viruses during a vaccine mismatch season.

Prognostic clinical decision support for pneumonia in the emergency department: A randomized trial.

BACKGROUND: Hospitalization rates for childhood pneumonia vary widely. Risk-based clinical decision support (CDS) interventions may reduce unwarranted variation. METHODS: We conducted a pragmatic randomized trial in two US pediatric emergency departments (EDs) comparing electronic health record (EHR)-integrated prognostic CDS versus usual care for promoting appropriate ED disposition in children (<18 years) with pneumonia. Encounters were randomized 1:1 to usual care versus custom CDS featuring a validated pneumonia severity score predicting risk for severe in-hospital outcomes. Clinicians retained full decision-making authority. The primary outcome was inappropriate ED disposition, defined as early transition to lower- or higher-level care. Safety and implementation outcomes were also evaluated. RESULTS: The study enrolled 536 encounters (269 usual care and 267 CDS). Baseline characteristics were similar across arms. Inappropriate disposition occurred in 3% of usual care encounters and 2% of CDS encounters (adjusted odds ratio: 0.99, 95% confidence interval: [0.32, 2.95]) Length of stay was also similar and adverse safety outcomes were uncommon in both arms. The tool's custom user interface and content were viewed as strengths by surveyed clinicians (>70% satisfied). Implementation barriers include intrinsic (e.g., reaching the right person at the right time) and extrinsic factors (i.e., global pandemic). CONCLUSIONS: EHR-based prognostic CDS did not improve ED disposition decisions for children with pneumonia. Although the intervention's content was favorably received, low subject accrual and workflow integration problems likely limited effectiveness. Clinical Trials Registration: NCT06033079.

User-Centered Design and Implementation of an Interoperable FHIR Application for Pediatric Pneumonia Prognostication in a Randomized Trial.

OBJECTIVE: To support a pragmatic, electronic health record (EHR)-based randomized controlled trial, we applied user-centered design (UCD) principles, evidence-based risk communication strategies, and interoperable software architecture to design, test, and deploy a prognostic tool for children in emergency departments (EDs) with pneumonia. METHODS: Risk for severe in-hospital outcomes was estimated using a validated ordinal logistic regression model to classify pneumonia severity. To render the results usable for ED clinicians, we created an integrated SMART on FHIR web application built for interoperable use in two pediatric EDs using different EHR vendors: Epic and Cerner. We followed a UCD framework, including problem analysis and user research, conceptual design and early prototyping, user interface development, formative evaluation, and post-deployment summative evaluation. RESULTS: Problem analysis and user research from 39 clinicians and nurses revealed user preferences for risk aversion, accessibility, and timing of risk communication. Early prototyping and iterative design incorporated evidence-based design principles, including numeracy, risk framing, and best-practice visualization techniques. After rigorous unit and end-to-end testing, the application was successfully deployed in both EDs, which facilitatd enrollment, randomization, model visualization, data capture, and reporting for trial purposes. CONCLUSIONS: The successful implementation of a custom application for pneumonia prognosis and clinical trial support in two health systems on different EHRs demonstrates the importance of UCD, adherence to modern clinical data standards, and rigorous testing. Key lessons included the need for understanding users' real-world needs, regular knowledge management, application maintenance, and the recognition that FHIR applications require careful configuration for interoperability.

The development of a novel natural language processing tool to identify pediatric chest radiograph reports with pneumonia.

Objective: Chest radiographs are frequently used to diagnose community-acquired pneumonia (CAP) for children in the acute care setting. Natural language processing (NLP)-based tools may be incorporated into the electronic health record and combined with other clinical data to develop meaningful clinical decision support tools for this common pediatric infection. We sought to develop and internally validate NLP algorithms to identify pediatric chest radiograph (CXR) reports with pneumonia. Materials and methods: We performed a retrospective study of encounters for patients from six pediatric hospitals over a 3-year period. We utilized six NLP techniques: word embedding, support vector machines, extreme gradient boosting (XGBoost), light gradient boosting machines Naïve Bayes and logistic regression. We evaluated their performance of each model from a validation sample of 1,350 chest radiographs developed as a stratified random sample of 35% admitted and 65% discharged patients when both using expert consensus and diagnosis codes. Results: Of 172,662 encounters in the derivation sample, 15.6% had a discharge diagnosis of pneumonia in a primary or secondary position. The median patient age in the derivation sample was 3.7 years (interquartile range, 1.4-9.5 years). In the validation sample, 185/1350 (13.8%) and 205/1350 (15.3%) were classified as pneumonia by content experts and by diagnosis codes, respectively. Compared to content experts, Naïve Bayes had the highest sensitivity (93.5%) and XGBoost had the highest F1 score (72.4). Compared to a diagnosis code of pneumonia, the highest sensitivity was again with the Naïve Bayes (80.1%), and the highest F1 score was with the support vector machine (53.0%). Conclusion: NLP algorithms can accurately identify pediatric pneumonia from radiography reports. Following external validation and implementation into the electronic health record, these algorithms can facilitate clinical decision support and inform large database research.

Vaccination Beliefs and Attitudes of Lactating People During the SARS-CoV-2 Pandemic.

BACKGROUND: Pregnant and recently pregnant people have lower vaccination rates against SARS-CoV-2 than the general population, despite increased risk of adverse outcomes from infection. Little is known about vaccine hesitancy in this population. RESEARCH AIM: To characterize SARS-CoV-2 and other vaccine attitudes of lactating people who accepted the SARS-CoV-2 vaccine, describing their vaccine experiences to further contextualize their beliefs. METHODS: A prospective cross-sectional online survey design was used. We administered the survey to 100 lactating people in Pennsylvania from April to August 2021, upon enrollment into a longitudinal study investigating SARS-CoV-2 vaccine antibodies in human milk. This survey assessed SARS-CoV-2 vaccine attitudes, vaccine counseling from providers, and vaccine decision making. Associations between vaccination timing and beliefs were analyzed by Pearson chi-square. RESULTS: Of 100 respondents, all received ≥ 1 SARS-CoV-2 vaccine before or shortly after enrollment, with 44% (n = 44) vaccinated in pregnancy and 56% (n = 56) while lactating. Participants reported vaccination counseling by obstetric (n = 48; 70%) and pediatric (n = 25; 36%) providers. Thirty-two percent (n = 32) received no advice on SARS-CoV-2 vaccination from healthcare providers, while 69% (n = 69) were counseled that vaccination was safe and beneficial.While 6% (n = 6) and 5% (n = 5) reported concerns about the safety of maternal vaccines for lactating people or their infants, respectively, 12% (n = 12) and 9% (n = 9) expressed concerns about the safety of maternal SARS-CoV-2 vaccination in particular. CONCLUSIONS: Despite high uptake of SARS-CoV-2 vaccine among participants, safety concerns persisted, with many reporting a lack of direct counseling from providers. Future research should investigate how variability in provider counseling affects SARS-CoV-2 vaccine uptake in perinatal populations.