Thrombosis with thrombocytopenia syndrome (TTS) and vaccine-induced immune thrombocytopenia and thrombosis (VITT): Brighton Collaboration case definitions and guidelines for data collection, analysis, and presentation of immunisation safety data

This is a revision of the online November 2021 Brighton thrombosis with thrombocytopenia syndrome (TTS) case definition and a new Brighton Collaboration case definition for vaccine-induced immune thrombocytopenia and thrombosis (VITT). These case definitions are intended for use in clinical trials and post-licensure pharmacovigilance activities to facilitate safety data comparability across multiple settings. They are not intended to guide clinical management. The case definitions were developed by a group of subject matter and Brighton Collaboration process experts as part of the Coalition for Epidemic Preparedness Innovations (CEPI)-funded Safety Platform for Evaluation of vACcines (SPEAC). The case definitions, each with defined levels of diagnostic certainty, are based on relevant published evidence and expert consensus and are accompanied by specific guidelines for TTS and VITT data collection and analysis. The document underwent peer review by a reference group of vaccine safety stakeholders and haematology experts to ensure case definition useability, applicability and scientific integrity.

Maternal COVID-19 Vaccination and Prevention of Symptomatic Infection in Infants

BACKGROUND AND OBJECTIVES

Maternal vaccination may prevent infant coronavirus disease 2019 (COVID-19). We aimed to quantify protection against infection from maternally derived vaccine-induced antibodies in the first 6 months of an infant's life.

METHODS

Infants born to mothers vaccinated during pregnancy with 2 or 3 doses of a messenger RNA COVID-19 vaccine (nonboosted or boosted, respectively) had full-length spike (Spike) immunoglobulin G (IgG), pseudovirus 614D, and live virus D614G, and omicron BA.1 and BA.5 neutralizing antibody (nAb) titers measured at delivery. Infant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was determined by verified maternal-report and laboratory confirmation through prospective follow-up to 6 months of age between December 2021 and July 2022. The risk reduction for infection by dose group and antibody titer level was estimated in separate models.

RESULTS

Infants of boosted mothers (n = 204) had significantly higher Spike IgG, pseudovirus, and live nAb titers at delivery than infants of nonboosted mothers (n = 271), and were 56% less likely to acquire infection in the first 6 months (P = .03). Irrespective of boost, for each 10-fold increase in Spike IgG titer at delivery, the infant's risk of acquiring infection was reduced by 47% (95% confidence interval 8%-70%; P = .02). Similarly, a 10-fold increase in pseudovirus titers against Wuhan Spike, and live virus nAb titers against D614G, and omicron BA.1 and BA.5 at delivery were associated with a 30%, 46%, 56%, and 60% risk reduction, respectively.

CONCLUSIONS

Higher transplacental binding and nAb titers substantially reduced the risk of SARS-CoV-2 infection in infants, and a booster dose amplified protection during a period of omicron predominance. Until infants are age-eligible for vaccination, maternal vaccination provides passive protection against symptomatic infection during early infancy.

Remdesivir for COVID-19 in Hospitalized Children: A Phase 2/3 Study

OBJECTIVES

Remdesivir decreases the risk of SARS-CoV-2 infection progressing to severe disease in adults. This study evaluated remdesivir safety and pharmacokinetics in infants and children.

METHODS

This was a phase 2/3, open-label trial in children aged 28 days to 17 years hospitalized for polymerase chain reaction-confirmed SARS-CoV-2 infection. Participants received for ≤10 days once-daily intravenous remdesivir doses defined using physiologically based pharmacokinetic modeling (for ≥40 kg, 200 mg day 1, then 100 mg/day; for age ≥28 days and ≥3 to <40 kg, 5 mg/kg day 1, then 2.5 mg/kg/day). Sparse pharmacokinetic samples were analyzed using population-pharmacokinetic approaches for remdesivir and metabolites GS-704277 and GS-441524.

RESULTS

Among 53 participants, at enrollment the median (Q1, Q3) number of days of COVID-19 symptoms was 5 (3, 7) and hospitalization was 1 (1, 3). Underlying conditions included obesity in 19 (37%), asthma in 11 (21%), and cardiac disorders in 11 (21%). Median duration of remdesivir treatment was 5 days (range, 1-10). Remdesivir treatment had no new apparent safety trends. Two participants discontinued treatment because of adverse events including elevated transaminases; both had elevated transaminases at baseline. Three deaths occurred during treatment (and 1 after). When compared with phase 3 adult data, estimated mean pediatric parameters (area under the concentration-time curve over 1 dosing interval, AUCτ, Cmax, and Cτ) were largely overlapping but modestly increased (remdesivir, 33%-129%; GS-704277, 37%-124%; GS-441524, 0%-60%). Recovery occurred for 62% of participants on day 10 and 83% at last assessment.

CONCLUSIONS

In infants and children with COVID-19, the doses of remdesivir evaluated provided drug exposure similar to adult dosing. In this study with a small sample size, no new safety concerns were observed.

The Durability of Antibody Responses of Two Doses of High-Dose Relative to Two Doses of Standard-Dose Inactivated Influenza Vaccine in Pediatric Hematopoietic Cell Transplant Recipients: A Multi-Center Randomized Controlled Trial

BACKGROUND

Our previous study established a 2-dose regimen of high-dose trivalent influenza vaccine (HD-TIV) to be immunogenically superior compared to a 2-dose regimen of standard-dose quadrivalent influenza vaccine (SD-QIV) in pediatric allogeneic hematopoietic cell transplant (HCT) recipients. However, the durability of immunogenicity and the role of time post-HCT at immunization as an effect modifier are unknown.

METHODS

This phase II, multi-center, double-blinded, randomized controlled trial compared HD-TIV to SD-QIV in children 3-17 years old who were 3-35 months post-allogeneic HCT, with each formulation administered twice, 28-42 days apart. Hemagglutination inhibition (HAI) titers were measured at baseline, 28-42 days following each dose, and 138-222 days after the second dose. Using linear mixed effects models, we estimated adjusted geometric mean HAI titer ratios (aGMR: HD-TIV/SD-QIV) to influenza antigens. Early and late periods were defined as 3-5 and 6-35 months post-HCT, respectively.

RESULTS

During 3 influenza seasons (2016-2019), 170 participants were randomized to receive HD-TIV (n = 85) or SD-QIV (n = 85). HAI titers maintained significant elevations above baseline for both vaccine formulations, although the relative immunogenic benefit of HD-TIV to SD-QIV waned during the study. A 2-dose series of HD-TIV administered late post-HCT was associated with higher GMTs compared to the early post-HCT period (late group: A/H1N1 aGMR = 2.16, 95% confidence interval [CI] = [1.14-4.08]; A/H3N2 aGMR = 3.20, 95% CI = [1.60-6.39]; B/Victoria aGMR = 1.91, 95% CI = [1.01-3.60]; early group: A/H1N1 aGMR = 1.03, 95% CI = [0.59-1.80]; A/H3N2 aGMR = 1.23, 95% CI = [0.68-2.25]; B/Victoria aGMR = 1.06, 95% CI = [0.56-2.03]).

CONCLUSIONS

Two doses of HD-TIV were more immunogenic than SD-QIV, especially when administered ≥6 months post-HCT. Both groups maintained higher titers compared to baseline throughout the season.

CLINICAL TRIALS REGISTRATION

NCT02860039.

Body surface area compared to body weight dosing of valganciclovir is associated with increased toxicity in pediatric solid organ transplantation recipients

Optimal dosing of valganciclovir (VGCV) for cytomegalovirus (CMV) prevention in pediatric solid organ transplantation recipients (SOTR) is controversial. Dosing calculated based on body surface area (BSA) and creatinine clearance is recommended but simplified body weight (BW) dosing is often prescribed. We conducted a retrospective 6-center study to compare safety and efficacy of these strategies in the first-year posttransplant There were 100 (24.2%) pediatric SOTR treated with BSA and 312 (75.7%) with BW dosing. CMV DNAemia was documented in 31.0% vs 23.4% (P = .1) at any time during the first year and breakthrough DNAemia in 16% vs 12.2% (P = .3) of pediatric SOTR receiving BSA vs BW dosing, respectively. However, neutropenia (50% vs 29.3%, P <.001), lymphopenia (51% vs 15.0%, P <.001), and acute kidney injury causing treatment modification (8.0% vs 1.8%, P <.001) were documented more frequently during prophylaxis in pediatric SOTR receiving BSA vs BW dosing. The adjusted odds ratio of VGCV-attributed toxicities comparing BSA and BW dosing was 2.3 (95% confidence interval [CI], 1.4-3.7] for neutropenia, 7.0 (95% CI, 3.9-12.4) for lymphopenia, and 4.6 (95% CI, 2.2-9.3) for premature discontinuation or dose reduction of VGCV, respectively. Results demonstrate that BW dosing is associated with significantly less toxicity without any increase in CMV DNAemia.

Are the first 1,000 days of life a neglected vital period to prevent the impact on maternal and infant morbimortality of infectious diseases in Latin America? Proceedings of a workshop of experts from the Latin American Pediatric Infectious Diseases Society, SLIPE

While the first 1,000 days of life are a critical period in child's development, limited information on the main determinants affecting this period in the Latin America and the Caribbean (LAC) region is available. Therefore, the Latin American Pediatric Infectious Diseases Society (SLIPE) held an ad hoc workshop in May 2022 with an expert panel designed to analyze the main factors impacting the development of childhood in the region during this period and the main causes of maternal infant morbimortality. The aim was to identify priorities, generate recommendations, and advise practical actions to improve this situation. Considerations were made about the challenges involved in bridging the gap that separates the region from more developed countries regarding an optimal early childhood and maternal care. Extensive discussion was conducted to reach consensus recommendations on general strategies intended to reduce maternal and infant mortality associated with infections and immune-preventable diseases during the first 1,000 days of life in LAC.

Safety and Immunogenicity of Live Viral Vaccines in a Multicenter Cohort of Pediatric Transplant Recipients

Importance

Live vaccines (measles-mumps-rubella [MMR] and varicella-zoster virus [VZV]) have not been recommended after solid organ transplant due to concern for inciting vaccine strain infection in an immunocompromised host. However, the rates of measles, mumps, and varicella are rising nationally and internationally, leaving susceptible immunocompromised children at risk for life-threating conditions.

Objective

To determine the safety and immunogenicity of live vaccines in pediatric liver and kidney transplant recipients.

Design, Setting, and Participants

This cohort study included select pediatric liver and kidney transplant recipients who had not completed their primary MMR and VZV vaccine series and/or who displayed nonprotective serum antibody levels at enrollment between January 1, 2002, and February 28, 2023. Eligibility for live vaccine was determined by individual US pediatric solid organ transplant center protocols.

Exposures

Exposure was defined as receipt of a posttransplant live vaccine. Transplant recipients received 1 to 3 doses of MMR vaccine and/or 1 to 3 doses of VZV vaccine.

Main Outcome and Measure

Safety data were collected following each vaccination, and antibody levels were obtained at 0 to 3 months and 1 year following vaccination. Comparisons were performed using Mann-Whitney U test, and factors associated with development of postvaccination protective antibodies were explored using univariate analysis.

Results

The cohort included 281 children (270 [96%] liver, 9 [3%] kidney, 2 [1%] liver-kidney recipients) from 18 centers. The median time from transplant to enrollment was 6.3 years (IQR, 3.4-11.1 years). The median age at first posttransplant vaccine was 8.9 years (IQR, 4.7-13.8 years). A total of 202 of 275 (73%) children were receiving low-level monotherapy immunosuppression at the time of vaccination. The majority of children developed protective antibodies following vaccination (107 of 149 [72%] varicella, 130 of 152 [86%] measles, 100 of 120 [83%] mumps, and 124 of 125 [99%] rubella). One year post vaccination, the majority of children who initially mounted protective antibodies maintained this protection (34 of 44 [77%] varicella, 45 of 49 [92%] measles, 35 of 42 [83%] mumps, 51 of 54 [94%] rubella). Five children developed clinical varicella, all of which resolved within 1 week. There were no cases of measles or rubella and no episodes of graft rejection within 1 month of vaccination. There was no association between antibody response and immunosuppression level at the time of vaccination.

Conclusions and Relevance

The findings suggest that live vaccinations may be safe and immunogenic after solid organ transplant in select pediatric recipients and can offer protection against circulating measles, mumps, and varicella.

Cumulative Febrile, Respiratory, and Gastrointestinal Illness Among Infants in Rural Guatemala and Association With Neurodevelopmental and Growth Outcomes

BACKGROUND

Infectious disease exposures in early life are increasingly recognized as a risk factor for poor subsequent growth and neurodevelopment. We aimed to evaluate the association between cumulative illness with neurodevelopment and growth outcomes in a birth cohort of Guatemalan infants.

METHODS

From June 2017 to July 2018, infants 0-3 months of age living in a resource-limited region of rural southwest Guatemala were enrolled and underwent weekly at-home surveillance for caregiver-reported cough, fever, and vomiting/diarrhea. They also underwent anthropometric assessments and neurodevelopmental testing with the Mullen Scales of Early Learning (MSEL) at enrollment, 6 months, and 1 year.

RESULTS

Of 499 enrolled infants, 430 (86.2%) completed all study procedures and were included in the analysis. At 12-15 months of age, 140 (32.6%) infants had stunting (length-for-age Z [LAZ] score < -2 SD) and 72 (16.7%) had microcephaly (occipital-frontal circumference [OFC] < -2 SD). In multivariable analysis, greater cumulative instances of reported cough illness (beta = -0.08/illness-week, P = 0.06) and febrile illness (beta = -0.36/illness-week, P < 0.001) were marginally or significantly associated with lower MSEL Early Learning Composite (ELC) Score at 12-15 months, respectively; there was no association with any illness (cough, fever, and/or vomiting/diarrhea; P = 0.27) or with cumulative instances of diarrheal/vomiting illness alone ( P = 0.66). No association was shown between cumulative instances of illness and stunting or microcephaly at 12-15 months.

CONCLUSIONS

These findings highlight the negative cumulative consequences of frequent febrile and respiratory illness on neurodevelopment during infancy. Future studies should explore pathogen-specific illnesses, host response associated with these syndromic illnesses, and their association with neurodevelopment.

COVID-19 booster vaccination during pregnancy enhances maternal binding and neutralizing antibody responses and transplacental antibody transfer to the newborn

The immune response to COVID-19 booster vaccinations during pregnancy for mothers and their newborns and the functional response of vaccine-induced antibodies against Omicron variants are not well characterized. We conducted a prospective, multicenter cohort study of participants vaccinated during pregnancy with primary or booster mRNA COVID-19 vaccines from July 2021 to January 2022 at 9 academic sites. We determined SARS-CoV-2 binding and live virus and pseudovirus neutralizing antibody (nAb) titers pre- and post-vaccination, and at delivery for both maternal and infant participants. Immune responses to ancestral and Omicron BA.1 SARS-CoV-2 strains were compared between primary and booster vaccine recipients in maternal sera at delivery and in cord blood, after adjusting for days since last vaccination. A total of 240 participants received either Pfizer or Moderna mRNA vaccine during pregnancy (primary 2-dose series: 167; booster dose: 73). Booster vaccination resulted in significantly higher binding and nAb titers, including to the Omicron BA.1 variant, in maternal serum at delivery and in cord blood compared to a primary 2-dose series (range 0.44-0.88 log10 higher, p < 0.0001 for all comparisons). Live virus nAb to Omicron BA.1 were present at delivery in 9 % (GMT ID50 12.7) of Pfizer and 22 % (GMT ID50 14.7) of Moderna primary series recipients, and in 73 % (GMT ID50 60.2) of mRNA boosted participants (p < 0.0001), although titers were significantly lower than to the D614G strain. Transplacental antibody transfer was efficient for all regimens with median transfer ratio range: 1.55-1.77 for IgG, 1.00-1.78 for live virus nAb and 1.79-2.36 for pseudovirus nAb. COVID-19 mRNA vaccination during pregnancy elicited robust immune responses in mothers and efficient transplacental antibody transfer to the newborn. A booster dose during pregnancy significantly increased maternal and cord blood binding and neutralizing antibody levels, including against Omicron BA.1. Findings support the use of a booster dose of COVID-19 vaccine during pregnancy.

Standardizing case definitions for monitoring the safety of maternal vaccines globally: GAIA definitions, a review of progress to date

In 2014, the Global Alignment on Immunization safety Assessment in pregnancy consortium (GAIA) was formed, with the goal of developing a harmonized, globally-concerted approach to actively monitor the safety of vaccines in pregnancy. A total of 26 standardized definitions for the classification of adverse events have been developed. The aim of this review was to identify and describe studies undertaken to assess the performance of these definitions. A literature search was undertaken to identify published studies assessing the performance of the definitions, and reference lists were snowballed. Data were abstracted by two investigators and a narrative review of the results is presented. Four studies that have evaluated 13 GAIA case definitions (50%) were identified. Five case definitions have been assessed in high-income settings only. Recommendations have been made by the investigators to improve the performance of the definitions. These include ensuring consistency across definitions, removal of the potential for ambiguity or variations in interpretation and ensuring that higher-level criteria are acceptable at lower levels of confidence. Future research should prioritize the key case definitions that have not been assessed in low- and middle-income settings, as well as the 13 that have not undergone any validation.

Palivizumab Prophylaxis in Infants and Young Children at Increased Risk of Hospitalization for Respiratory Syncytial Virus Infection

Guidance from the American Academy of Pediatrics (AAP) for the use of palivizumab prophylaxis against respiratory syncytial virus (RSV) was first published in a policy statement in 1998. AAP recommendations have been updated periodically to reflect the most recent literature regarding children at greatest risk of severe RSV disease. Since the last update in 2014, which refined prophylaxis guidance to focus on those children at greatest risk, data have become available regarding the seasonality of RSV circulation, the incidence and risk factors associated with bronchiolitis hospitalizations, and the potential effects of the implementation of prophylaxis recommendations on hospitalization rates of children with RSV infection. This technical report summarizes the literature review by the Committee on Infectious Diseases, supporting the reaffirmation of the 2014 AAP policy statement on palivizumab prophylaxis among infants and young children at increased risk of hospitalization for RSV infection. Review of publications since 2014 did not support a change in recommendations for palivizumab prophylaxis and continues to endorse the guidance provided in the 2021 Red Book.

Incidence Rates of Medically Attended COVID-19 in Infants Less Than 6 Months of Age

BACKGROUND

Studies suggest infants may be at increased risk of severe coronavirus disease 2019 (COVID-19) relative to older children, but few data exist regarding the incidence of COVID-19 episodes and associated risk factors. We estimate incidence rates and describe characteristics associated with medically attended COVID-19 episodes among infants younger than 6 months of age.

METHODS

We analyzed electronic medical record data from a cohort of infants born March 1, 2020-February 28, 2021. Data from 3 health care delivery systems included demographic characteristics, maternal and infant outpatient visit and hospitalization diagnoses and severe acute respiratory syndrome coronavirus syndrome 2 (SARS-CoV-2) test results. Medically attended COVID-19 episodes were defined by positive SARS-CoV-2 clinical tests and/or COVID-19 diagnosis codes during medical care visits. Unadjusted and site-adjusted incidence rates by infant month of age, low and high SARS-CoV-2 circulation periods and maternal COVID-19 diagnosis were calculated.

RESULTS

Among 18,192 infants <6 months of age whose mothers received prenatal care within the 3 systems, 173 (1.0%) had medically attended COVID-19 episodes. Incidence rates were highest among infants under 1 month of age (2.0 per 1000 person-weeks) and 1 month (2.0 per 1000 person-weeks) compared with older infants. Incidence rates were also higher for infants born to women with postpartum COVID-19 compared with women without known COVID-19 and women diagnosed with COVID-19 during pregnancy.

CONCLUSIONS

Infants of women with postpartum COVID-19 had a higher risk of medically attended COVID-19 than infants born to mothers who were diagnosed during pregnancy or never diagnosed underscoring the importance of COVID-19 prevention measures for their household members and caregivers to prevent infections in infants.

Safety of COVID-19 vaccines during pregnancy: A systematic review and meta-analysis

Background

Assessment of COVID-19 vaccines safety during pregnancy is urgently needed.

Methods

We conducted a systematic review and meta-analysis to evaluate the safety of COVID-19 vaccines, including their components and technological platforms used in other vaccines during pregnancy and animal studies to complement direct evidence. We searched literature databases from its inception to September 2021 without language restriction, COVID-19 vaccine websites, and reference lists of other systematic reviews and the included studies. Pairs of reviewers independently selected, data extracted, and assessed the risk of bias of the studies. Discrepancies were resolved by consensus. (PROSPERO CRD42021234185).

Results

We retrieved 8,837 records from the literature search; 71 studies were included, involving 17,719,495 pregnant persons and 389 pregnant animals. Most studies (94%) were conducted in high-income countries, were cohort studies (51%), and 15% were classified as high risk of bias. We identified nine COVID-19 vaccine studies, seven involving 309,164 pregnant persons, mostly exposed to mRNA vaccines. Among non-COVID-19 vaccines, the most frequent exposures were AS03 and aluminum-based adjuvants.

A meta-analysis of studies that adjusted for potential confounders showed no association with adverse outcomes, regardless of the vaccine or the trimester of vaccination.

Neither the reported rates of adverse pregnancy outcomes nor reactogenicity exceeded expected background rates, which was the case for ASO3- or aluminum-adjuvanted non-COVID-19 vaccines in the proportion meta-analyses of uncontrolled studies/arms. The only exception was postpartum hemorrhage after COVID-19 vaccination (10.40%; 95% CI: 6.49-15.10%), reported by two studies; however, the comparison with non-exposed pregnant persons, available for one study, found non-statistically significant differences (adjusted OR 1.09; 95% CI 0.56-2.12). Animal studies showed consistent results with studies in pregnant persons.

Conclusion

We found no safety concerns for currently administered COVID-19 vaccines during pregnancy. Additional experimental and real-world evidence could enhance vaccination coverage. Robust safety data for non-mRNA-based COVID-19 vaccines are still needed.

Safety, immunogenicity, and effectiveness of COVID-19 vaccines for pregnant persons: A protocol for systematic review and meta analysis

INTRODUCTION

Numerous vaccines have been evaluated and approved for coronavirus disease 2019 (COVID-19). Since pregnant persons have been excluded from most clinical trials of COVID-19 vaccines, sufficient data regarding the safety of these vaccines for the pregnant person and their fetus have rarely been available at the time of product licensure. However, as COVID-19 vaccines have been deployed, data on the safety, reactogenicity, immunogenicity, and efficacy of COVID-19 vaccines for pregnant persons and neonates are becoming increasingly available. A living systematic review and meta-analysis of the safety and effectiveness of COVID-19 vaccines for pregnant persons and newborns could provide the information necessary to help guide vaccine policy decisions.

METHODS AND ANALYSIS

We aim to conduct a living systematic review and meta-analysis based on biweekly searches of medical databases (e.g., MEDLINE, EMBASE, CENTRAL) and clinical trial registries to systematically identify relevant studies of COVID-19 vaccines for pregnant persons. Pairs of reviewers will independently select, extract data, and conduct risk of bias assessments. We will include randomized clinical trials, quasi-experimental studies, cohort, case-control, cross-sectional studies, and case reports. Primary outcomes will be the safety, efficacy, and effectiveness of COVID-19 vaccines in pregnant persons, including neonatal outcomes. Secondary outcomes will be immunogenicity and reactogenicity. We will conduct paired meta-analyses, including prespecified subgroup and sensitivity analyses. We will use the grading of recommendations assessment, development, and evaluation approach to evaluate the certainty of evidence.

Application of organ dysfunction assessment scores following pediatric lung transplantation

OBJECTIVE

Organ dysfunction (OD) after lung transplantation can reflect preoperative organ failure, intraoperative acute organ damage and post-operative complications. We assessed two OD scoring systems, both the PEdiatric Logistic Organ Dysfunction (PELOD) and the pediatric Sequential Organ Failure Assessment (pSOFA) scores, in recognizing risk factors for morbidity as well as recipients with prolonged post-transplant morbidity.

DESIGN

Medical records of recipients from January 2009 to March 2016 were reviewed. PELOD and pSOFA scores were calculated on post-transplant days 1-3. Risk factors assessed included cystic fibrosis (CF), prolonged surgical time and worst primary graft dysfunction (PGD) score amongst others. Patients were classified into three groups based on their initial scores (group A) and subsequent trends either uptrending (group B) or downtrending (group C). Morbidity outcomes were compared between these groups.

RESULTS

Total 98 patients were enrolled aged 0-20 years. Risk factors for higher pSOFA scores ≥ 5 on day 1 included non-CF diagnosis and worst PGD scores (p = .0006 and p = .03, respectively). Kruskal Wallis analysis comparing pSOFA group A versus B versus C scores showed significantly prolonged ventilatory days (median 1 vs. 4 vs. 2, p = .0028) and ICU days (median 4 vs. 10 vs. 6, p = .007). Similarly, PELOD group A versus B versus C scores showed significantly prolonged ventilatory days (1 vs. 5 vs. 2, p = < .0001).

CONCLUSION

Implementing pSOFA scores bedside is a more effective tool compared to PELOD in identifying risk factors for worsened OD post-lung transplant and can be valuable in providing direction on morbidity outcomes in the ICU.

Sustained Within-season Vaccine Effectiveness Against Influenza-associated Hospitalization in Children: Evidence From the New Vaccine Surveillance Network, 2015-2016 Through 2019-2020

BACKGROUND

Adult studies have demonstrated within-season declines in influenza vaccine effectiveness (VE); data in children are limited.

METHODS

We conducted a prospective, test-negative study of children 6 months through 17 years hospitalized with acute respiratory illness at 7 pediatric medical centers during the 2015-2016 through 2019-2020 influenza seasons. Case-patients were children with an influenza-positive molecular test matched by illness onset to influenza-negative control-patients. We estimated VE [100% × (1 - odds ratio)] by comparing the odds of receipt of ≥1 dose of influenza vaccine ≥14 days before illness onset among influenza-positive children to influenza-negative children. Changes in VE over time between vaccination date and illness onset date were estimated using multivariable logistic regression.

RESULTS

Of 8430 children, 4653 (55%) received ≥1 dose of influenza vaccine. On average, 48% were vaccinated through October and 85% through December each season. Influenza vaccine receipt was lower in case-patients than control-patients (39% vs 57%, P < .001); overall VE against hospitalization was 53% (95% confidence interval [CI]: 46, 60%). Pooling data across 5 seasons, the odds of influenza-associated hospitalization increased 4.2% (-3.2%, 12.2%) per month since vaccination, with an average VE decrease of 1.9% per month (n = 4000, P = .275). Odds of hospitalization increased 2.9% (95% CI: -5.4%, 11.8%) and 9.6% (95% CI: -7.0%, 29.1%) per month in children ≤8 years (n = 3084) and 9-17 years (n = 916), respectively. These findings were not statistically significant.

CONCLUSIONS

We observed minimal, not statistically significant within-season declines in VE. Vaccination following current Advisory Committee on Immunization Practices (ACIP) guidelines for timing of vaccine receipt remains the best strategy for preventing influenza-associated hospitalizations in children.

Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

Respiratory syncytial virus prevention within reach: the vaccine and monoclonal antibody landscape

Respiratory syncytial virus is the second most common cause of infant mortality and a major cause of morbidity and mortality in older adults (aged >60 years). Efforts to develop a respiratory syncytial virus vaccine or immunoprophylaxis remain highly active. 33 respiratory syncytial virus prevention candidates are in clinical development using six different approaches: recombinant vector, subunit, particle-based, live attenuated, chimeric, and nucleic acid vaccines; and monoclonal antibodies. Nine candidates are in phase 3 clinical trials. Understanding the epitopes targeted by highly neutralising antibodies has resulted in a shift from empirical to rational and structure-based vaccine and monoclonal antibody design. An extended half-life monoclonal antibody for all infants is likely to be within 1 year of regulatory approval (from August, 2022) for high-income countries. Live-attenuated vaccines are in development for older infants (aged >6 months). Subunit vaccines are in late-stage trials for pregnant women to protect infants, whereas vector, subunit, and nucleic acid approaches are being developed for older adults. Urgent next steps include ensuring access and affordability of a respiratory syncytial virus vaccine globally. This review gives an overview of respiratory syncytial virus vaccines and monoclonal antibodies in clinical development highlighting different target populations, antigens, and trial results.

1096. Riding the Waves: Infection by SARS-CoV-2 Variants in Solid Organ Transplant Recipients at Texas Children’s Hospital

Background

Texas Children’s Hospital is the largest pediatric solid organ transplant (SOT) program in the US, performing heart, kidney, liver, and lung transplants. Limited data exist about SARS-CoV-2 infection (COVID-19) in the pediatric SOT population. We evaluated the impact of different SARS-CoV-2 variants in a cohort of PCR positive SOT recipients.

Methods

SOT recipients with a positive SARS-CoV-2 PCR test from 3/1/2020 to 2/28/2022 were included in the cohort. The study period was divided into 3 eras based on the predominant circulating variant of SARS-CoV-2: 3/20-6/21 original strain/Alpha, 7/21-11/21 Delta, and 12/21-2/22 Omicron variants. Retrospective medical record review was performed; Chi-squared and Fischer exact test were used to compare groups.

Results

A total of 269 of 1031 (26%) SOT recipients tested positive for SARS-CoV-2 during the study period. By organ, 87/335 (26%) heart, 57/224 (25%) kidney, 92/405 (23%) liver, and 25/67 (37%) lung recipients had COVID-19 infection. By era, there were 99 (37%) original strain/ Alpha, 65 (24%) Delta, and 105 (39%) Omicron. The patients’ median age was 12.72 years (IQR 6.6, 15.1) with a minority of recipients being female (42%). Common comorbidities included hypertension (50%), obesity (13%), diabetes (10%), and chronic kidney disease (10%); 34% had no comorbidities aside from chronic immunosuppression post-transplant. Overall, 80% of recipients were symptomatic (Figure 1), and 50 (19%) required hospitalization. Hospitalization rates were highest (29%) during Delta, compared with 18% for original/Alpha and 13% for Omicron (p=0.02) eras. Need for respiratory support, ICU admission, and all-cause mortality did not vary by era (Table 1). Three SOT recipients (2 original/Alpha and 1 Delta) were diagnosed with multi-inflammatory syndrome in children (MIS-C).

Conclusion

Our study suggests that pediatric SOT recipients have a high risk for hospitalization and short-term complications with COVID-19; Omicron appears to cause less severe disease, including MIS-C. Additional studies are needed to understand long-term complications of COVID-19 in SOT recipients.

Disclosures

Elizabeth A. Moulton, MD, PhD, Pfizer: Grant/Research Support Flor M. Munoz, MD, MSc, Gilead: Grant/Research Support|Moderna: DSMB|Pfizer: DSMB.

2167. Use and Timing of Antiviral Therapy for Influenza in Hospitalized U.S. Children, 2016–2020

Background

According to the 2018 Infectious Diseases Society of America (IDSA) clinical practice guidelines and Centers for Disease Control and Prevention (CDC) guidance, clinicians should start antiviral treatment as soon as possible for children who are hospitalized with suspected or confirmed influenza. We assessed the use of influenza-specific antiviral therapy in children hospitalized with symptoms of acute respiratory illness and laboratory-confirmed influenza.

Methods

We conducted active, population-based surveillance of children hospitalized with fever and/or respiratory symptoms (12/01/2016–02/28/2020) at the seven U.S. medical centers that comprise the CDC New Vaccine Surveillance Network. We excluded children who did not undergo clinical testing (by rapid antigen testing or nucleic acid amplification test [NAAT]) or research testing (by NAAT) for influenza, those who presented out of influenza season (site- and season-specific), and those whose date of antiviral therapy or whether antiviral therapy was given was unknown. We assessed the use of influenza-specific antiviral therapy in this cohort and defined timely antiviral therapy as administration within 2 days of hospitalization.

Results

Of 11,275 eligible children, 1,149 (10.2%) tested positive for influenza by clinical and/or research assays (Table 1). Overall, 154 influenza cases (13.4%) were detected by clinical testing only, 428 (37.2%) by research testing only, and 567 (49.3%) by both. During their influenza-associated hospitalization, 620 children (54.0%) received influenza-specific antivirals, and therapy was timely in 572 cases (92.3%). Of those who tested positive clinically, 445/721 (61.7%) received timely antiviral therapy, 38 (5.3%) received delayed antiviral therapy, and 238 (33.0%) received no antiviral therapy. Oseltamivir was the antiviral used in all treated cases. The distribution of antiviral-treated cases varied by race and Hispanic origin and study site, but not by age at presentation or influenza season (Figure 1). Table 1

Demographic characteristics of 1,149 children with influenza enrolled in the New Vaccine Surveillance Network over four influenza seasons between December 1, 2016, and February 28, 2020. Figure 1Proportions of children with influenza enrolled in the New Vaccine Surveillance Network who received timely, delayed, or no antiviral therapy by age at presentation, race and Hispanic origin, study site, and influenza season (N=1,149).

Conclusion

Although antiviral therapy is recommended for all influenza-associated hospitalizations in children, antiviral prescribing remains suboptimal. Further studies would help identify and address barriers to antiviral therapy in children with influenza.

Disclosures

John Williams, MD, GlaxoSmithKline: Advisor/Consultant|Quidel: Advisor/Consultant Janet A. Englund, MD, AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, F(AAM), BioFire: Grant/Research Support|Luminex: Grant/Research Support Mary A. Staat, MD, MPH, Centers for Disease Control and Prevention: Grant/Research Support|Cepheid: Grant/Research Support|National Institute of Health: Grant/Research Support|Uptodate: Royalties Geoffrey A. Weinberg, MD, Merck & Co.: Honoraria|Merck & Co.: Honoraria for composing and reviewing textbook chapters, Merck Manual of Therapeutics Flor M. Munoz, MD, MSc, Gilead: Grant/Research Support|Moderna: DSMB|Pfizer: DSMB Christopher J Harrison, MD, Astellas: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Pediatric news: Honoraria|Pfizer: Grant/Research Support Natasha B. Halasa, MD, Quidel: Grant/Research Support|Quidel: equipment donation|Sanofi: Grant/Research Support|Sanofi: HAI testing and vaccine donation.

1588. Epidemiology of Chronic High Level (CHL) Epstein-Barr virus (EBV) DNAemia in Pediatric Solid Organ Transplant Recipients (SOTR) at Texas Children’s Hospital (TCH)

Background

EBV infections cause significant morbidity and mortality in pediatric SOTR and can be complicated by post-transplant lymphoproliferative disorder (PTLD). Contemporary data on CHL EBV DNAemia and the development of PTLD are limited.

Methods

A retrospective cohort study of patients ≤ 21 years of age who received heart, lung, liver, kidney, or multi-organ transplants at TCH between 2011–2018 was conducted. Primary outcome was CHL EBV DNAemia, defined as peripheral blood lymphocyte EBV values ≥ 500 copies/ug or whole blood EBV values ≥ 10,000 IU/mL for ≥ 6 months. Associations with CHL EBV DNAemia were measured using chi-squared or Fisher exact test and multivariate logistic regression. Time to CHL EBV DNAemia was assessed using Kaplan-Meier method.

Results

Among 687 SOTR (152 heart, 87 lung, 259 liver, 175 kidney, 14 multi-organ), 87 (13%) developed CHL EBV DNAemia; this included 15 (9%) heart, 9 (10%) lung, 59 (22%) liver, 2 (1%) kidney, and 2 (14%) multi-organ recipients. Receiving a heart [OR 2.1, 95% CI (2.1 – 62.4)], lung [7.7, 95% CI (1.5 – 39.3)], liver [OR 31.8, 95% CI (4.9 – 208.7)], or multi-organ [OR 18.3, 95% CI (2.0 – 170)] transplant and being 1–5 years of age [OR 4.0, 95% CI (1.6 – 9.8)] were associated with CHL EBV DNAemia. SOTR transplanted from 2015–2018 were less likely to develop CHL EBV DNAemia than those transplanted from 2011–2014 [OR 0.5, 95% CI (0.3 – 0.8)]. EBV risk status, CMV risk status, gender, and induction therapy were not associated with developing CHL EBV DNAemia.

The median maximum peripheral blood lymphocyte and whole blood EBV values for those with CHL EBV DNAemia were 9475 (993 – 258151) copies/ug and 22093 (564 – 550000) IU/mL, respectively. Organ transplanted (p< 0.01), age (p< 0.01), and EBV risk status (p< 0.01) were associated with time to CHL EBV DNAemia (Figure 1). PTLD occurred in 28 (4%) of SOTR; 14 (50%) had preceding CHL EBV DNAemia (p< 0.01).

Figure 1 Time to CHL EBV DNAemia.

Conclusion

This cohort of pediatric SOTR demonstrates a low prevalence of CHL EBV DNAemia and PTLD. Receiving a heart, lung, liver, or multi-organ transplant and being 1–5 years of age were associated with developing CHL EBV DNAemia. SOTR who developed CHL EBV DNAemia were more likely to develop PTLD, suggesting that further interventions targeting this group may be warranted.

Disclosures

Flor M. Munoz, MD, MSc, Gilead: Grant/Research Support Elizabeth A. Moulton, MD, PhD, Pfizer: Co-investigator for SARS-CoV-2 pediatric vaccine trials.

1075. The MET Project: Distinguishing Multisystem Inflammatory Syndrome in Children from Typhus Using Artificial Intelligence

Background

Multisystem inflammatory syndrome in children (MIS-C) following SARS-CoV-2 infection shares features with other inflammatory states, notably Kawasaki Disease. The rickettsial infection murine typhus is also in the differential for MIS-C in endemic areas. As the therapeutic approaches differ, it is essential to distinguish these disorders soon after presentation, well before confirmatory serologic testing results. Our objective was to develop an algorithm to accurately predict MIS-C versus typhus.

Methods

Retrospective review extracted demographic, clinical, and laboratory features available within 6 hours of presentation for 133 MIS-C and 87 typhus patients. 33 features were broken into 44 inputs and passed through an attention module to compute importance. Inputs were then entered into machine learning algorithms as MIS-C or typhus. Patients were divided into training and test cohorts respecting proportions in the dataset. An equation was built to calculate the “MET” (MIS-C versus endemic typhus) score.

Results

MIS-C patients were younger (8.4 v 11.2 years, p< 0.0001) and the majority (71%) presented on day 4-6 of fever; most typhus patients (84%) presented with ≥6 days (mean 4.9 v 7.3 days, p< 0.0001). Typhus patients were more likely to have rash (86% v 51%, p< 0.0001) and MIS-C patients red eyes (71% v 36%, p< 0.0001), other features were similar. MIS-C patients had higher C-reactive protein levels (17.7 v 9.8 mg/dL), procalcitonin (14.0 v 0.48 ng/mL), fibrinogen (558 v 394 mg/dL) and neutrophil-to-lymphocyte ratio (12 v 3.5), all p< 0.0001, other parameters were similar. MIS-C patients were also more likely to have elevated troponin (0.48 v 0.01 ng/mL, p< 0.0001) and require intensive care (66% v 6%, p< 0.0001). A long short term memory network outperformed 6 other models (99% accuracy using all 33 elements). The MET score predicted MIS-C versus typhus with 90% accuracy using only 10 features (sensitivity 90%, specificity 90%).

Conclusion

The clinical and laboratory similarities between typhus and MIS-C present challenges, but they can be reliably distinguished using artificial intelligence with as little as 10 features. Our ongoing interprofessional collaboration aims to make the MET score readily available to clinicians for use in patient encounters.

Disclosures

Flor M. Munoz, MD, MSc, Gilead: Grant/Research Support|Moderna: DSMB|Pfizer: DSMB Tiphanie Vogel, MD, PhD, Moderna: Advisor/Consultant|Novartis: Advisor/Consultant|Pfizer: Advisor/Consultant.

A new chapter in an evolving pandemic: Successful pediatric liver transplantation with SARS-CoV-2+ donors

BACKGROUND

Amid a viral pandemic with poorly understood transmissibility and pathogenicity in the pediatric patient, we report the first pediatric liver transplants utilizing allografts from SARS-CoV-2+ donors.

METHODS

We describe the outcomes of two pediatric liver transplant recipients who received organs from SARS-CoV-2 nucleic acid test-positive (NAT+) donors. Data were obtained through the respective electronic medical record system and UNet DonorNet platform.

RESULTS

The first donor was a 3-year-old boy succumbing to head trauma. One of four nasopharyngeal (NP) swabs and 1 of 3 bronchoalveolar lavage (BAL) NAT tests demonstrated SARS-CoV-2 infection before organ procurement. The second donor was a 16-month-old boy with cardiopulmonary arrest of unknown etiology. Three NAT tests (2 NP swab/1 BAL) prior to procurement failed to detect SARS-CoV-2. The diagnosis was made when the medical examiner repeated 2 NP swab NATs and an archive plasma NAT, all positive for SARS-CoV-2. Both 2-year-old recipients continue to do well 8 months post-transplant, with excellent graft function and no evidence of SARS-CoV-2 transmission.

CONCLUSIONS

This is the first report to describe successful pediatric liver transplantation from SARS-CoV-2+ donors. These data reinforce the adult transplant experience and support the judicious use of SARS-CoV-2+ donors for liver transplantation in children. With SARS-CoV-2 becoming endemic, the concern for donor-derived viral transmission must now be weighed against the realized benefit of life-saving transplantation in the pediatric population as we continue to work toward donor pool maximization.

Incorporating COVID-19 into Acute Febrile Illness Surveillance Systems, Belize, Kenya, Ethiopia, Peru, and Liberia, 2020-2021

Existing acute febrile illness (AFI) surveillance systems can be leveraged to identify and characterize emerging pathogens, such as SARS-CoV-2, which causes COVID-19. The US Centers for Disease Control and Prevention collaborated with ministries of health and implementing partners in Belize, Ethiopia, Kenya, Liberia, and Peru to adapt AFI surveillance systems to generate COVID-19 response information. Staff at sentinel sites collected epidemiologic data from persons meeting AFI criteria and specimens for SARS-CoV-2 testing. A total of 5,501 patients with AFI were enrolled during March 2020-October 2021; >69% underwent SARS-CoV-2 testing. Percentage positivity for SARS-CoV-2 ranged from 4% (87/2,151, Kenya) to 19% (22/115, Ethiopia). We show SARS-CoV-2 testing was successfully integrated into AFI surveillance in 5 low- to middle-income countries to detect COVID-19 within AFI care-seeking populations. AFI surveillance systems can be used to build capacity to detect and respond to both emerging and endemic infectious disease threats.