Assessing vaccine-induced immunity against pneumococcus, hepatitis A and B over a 9-year follow-up in pediatric liver transplant recipients: A nationwide retrospective study.

Pediatric liver transplant recipients are particularly at risk of infections. The most cost-effective way to prevent infectious complications is through vaccination, which can potentially prevent infections due to hepatitis B (HBV) virus, hepatitis A virus (HAV), and invasive pneumococcal diseases. Here, we performed a retrospective analysis of HBV, HAV, and pneumococcal immunity in pediatric liver transplant recipients between January 1, 2009, and December 31, 2020, to collect data on immunization and vaccine serology. A total of 94% (58/62) patients had available vaccination records. At transplant, 90% (45/50) were seroprotected against HBV, 63% (19/30) against HAV, and 78% (18/23) had pneumococcal immunity, but immunity against these 3 pathogens remained suboptimal during the 9-year follow-up. A booster vaccine was administered to only 20% to 40% of patients. Children who had received >4 doses of HBV vaccine and > 2 doses of HAV vaccine pretransplant displayed a higher overall seroprotection over time post-solid organ transplant. Our findings suggest that a serology-based approach should be accompanied by a more systematic follow-up of vaccination, with special attention paid to patients with an incomplete vaccination status at time of transplant.

Rituximab-to-vaccine interval on SARS-CoV-2 immunogenicity in children: The potential role of prior natural infection.

BACKGROUND: Treatment with anti-CD20 antibodies (rituximab) is used in both adults and children to treat various autoimmune and oncological diseases. Rituximab depletes B CD20+ cells and, thereby, antibody response to vaccines. This study aimed to examine the antibody response to mRNA-based COVID-19 vaccines in children aged 5-18 years undergoing rituximab treatment compared to healthy matched children. METHODS: Between 31 January and 18 July 2022, we conducted a prospective observational study at the Geneva University Hospitals, enrolling children aged 5-18 years under rituximab treatment who had received two mRNA-based SARS-CoV-2 vaccine doses. Controls were healthy volunteers with no significant medical conditions. Exclusion criteria included a recent SARS-CoV-2 infection. Blood samples were collected at day 60 (±30) and day 270 (±90) after the second vaccination. RESULTS: The rituximab-treated group exhibited significantly lower levels of antibodies specific to the anti-receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein than healthy controls at 60 (±30) days after the second vaccine dose (geometric mean concentration: 868.3 IU/mL in patients and 11,393 IU/mL in controls; p = .008). However, patients with a rituximab-to-vaccine interval shorter than 6 months and with evidence of a past infection (based on positive anti-N antibody levels) had a high level of anti-RBD antibodies. CONCLUSION: A past infection with SARS-CoV-2 may induce anti-RBD-specific memory B cells that can be re-activated by SARS-CoV-2 vaccination, even after rituximab-induced B-cell depletion. This suggests that it is possible to vaccinate earlier than 6 months after rituximab to develop a good antibody response, especially in the case of past SARS-CoV-2 infection.

Vaccine Immunity in Children After Hematologic Cancer Treatment: A Retrospective Single-center Study.

BACKGROUND: Children lose their vaccine-induced protection and are particularly vulnerable to vaccine-preventable diseases after chemotherapy. However, revaccination guidelines are heterogeneous, and there is often a lack of revaccination post-treatment. AIMS: We conducted a retrospective study of children with hematologic cancer to evaluate vaccine immunity before and after the end of treatment and to determine whether the current institutional revaccination program based on vaccine serology results was followed and effective. MATERIALS AND METHODS: Data of all children treated by chemotherapy between April 2015 and July 2021 were extracted from hospital medical records for analysis. Serum antibody levels and time of vaccination were evaluated for diphtheria, tetanus, Streptococcus pneumoniae , Haemophilus influenzae type b (Hib), measles, varicella, and hepatitis B. RESULTS: We included 31 patients (median age, 9 years). At cancer diagnosis, 90% of children were protected against tetanus, diphtheria, and measles; 65% to 67% were protected against pneumococcus and varicella; and 25% against hepatitis B. At the end of chemotherapy, 67% to 71% of patients were protected against tetanus, varicella, and measles; 40% remained protected against hepatitis B; and 27% to 33% against pneumococcus and diphtheria. Patients were revaccinated at various times after the end of treatment but not systematically. During the first-year post-treatment, 20% to 25% of children remained unprotected against pneumococcus, measles, and hepatitis B, one third against diphtheria, but all were protected against tetanus and varicella. CONCLUSIONS: An effective individualized vaccination program post-cancer based on serology results should be accompanied by an appropriate serology tracking method and follow-up to assess if booster doses are necessary. Our study supports vaccinating all children with a dose of the 13-valent pneumococcal conjugate at cancer diagnosis and at 3 months post-treatment with the combined diphtheria-tetanus-acellular pertussis/poliomyelitis vaccine/hepatitis B virus plus or minus Hib and 13-valent pneumococcal conjugate and meningococcal vaccine, including measles/mumps/rubella-varicella zoster virus vaccine if good immune reconstitution is present.

Organ Dysfunction in Children With Blood Culture-Proven Sepsis: Comparative Performance of Four Scores in a National Cohort Study.

OBJECTIVES: Previous studies applying Sepsis-3 criteria to children were based on retrospective analyses of PICU cohorts. We aimed to compare organ dysfunction criteria in children with blood culture-proven sepsis, including emergency department, PICU, and ward patients, and to assess relevance of organ dysfunctions for mortality prediction. DESIGN: We have carried out a nonprespecified, secondary analysis of a prospective dataset collected from September 2011 to December 2015. SETTING: Emergency departments, wards, and PICUs in 10 tertiary children's hospitals in Switzerland. PATIENTS: Children younger than 17 years old with blood culture-proven sepsis. We excluded preterm infants and term infants younger than 7 days old. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We compared the 2005 International Pediatric Sepsis Consensus Conference (IPSCC), Pediatric Logistic Organ Dysfunction-2 (PELOD-2), pediatric Sequential Organ Failure Assessment (pSOFA), and Pediatric Organ Dysfunction Information Update Mandate (PODIUM) scores, measured at blood culture sampling, to predict 30-day mortality. We analyzed 877 sepsis episodes in 807 children, with a 30-day mortality of 4.3%. Percentage with organ dysfunction ranged from 32.7% (IPSCC) to 55.3% (pSOFA). In adjusted analyses, the accuracy for identification of 30-day mortality was area under the curve (AUC) 0.87 (95% CI, 0.82-0.92) for IPSCC, 0.83 (0.76-0.89) for PELOD-2, 0.85 (0.78-0.92) for pSOFA, and 0.85 (0.78-0.91) for PODIUM. When restricting scores to neurologic, respiratory, and cardiovascular dysfunction, the adjusted AUC was 0.89 (0.84-0.94) for IPSCC, 0.85 (0.79-0.91) for PELOD-2, 0.87 (0.81-0.93) for pSOFA, and 0.88 (0.83-0.93) for PODIUM. CONCLUSIONS: IPSCC, PELOD-2, pSOFA, and PODIUM performed similarly to predict 30-day mortality. Simplified scores restricted to neurologic, respiratory, and cardiovascular dysfunction yielded comparable performance.

Highlights from the 12th congress of the international pediatric transplant association, Austin, Texas 2023.

The 12th Congress of the (IPTA) event in Austin, Texas, had over 400 attendees from 40 countries. The attendees included a diverse mix of pediatric transplant professionals from several specialties including physicians, surgeons, scientists, nurses, organ procurement personnel, advance transplant providers, pharmacists, administrators, fellows, residents, and students. The 4-day event featured nearly 200 abstracts, 90 oral presentations, 24 mini oral presentations, and more than 80 poster presentations. All of these presentations encouraged vibrant discussions and supported the exchange of new clinical and basic science information regarding clinical care management, basic science research, socioeconomic, and ethical and organ donation issues relevant to pediatric transplantation. We briefly describe here the highest scored presented abstracts at IPTA 2023 that are divided into two categories: clinical and basic sciences.

Viremia as a predictor of absence of serious bacterial infection in children with fever without source.

Most children with fever without source (FWS) require diagnostic laboratory tests to exclude a serious bacterial infection (SBI), often followed by admission and empirical antibiotics. As febrile children with a viral infection are less likely to have a SBI, identifying patients with systemic viral infection could contribute to exclude SBI. We evaluated whether the presence of virus in the blood could be used as a biomarker to rule out SBI. Children < 3 years old with FWS were prospectively enrolled and had real-time (reverse-transcription) PCR performed on the blood for adenovirus, enterovirus, parechovirus, and HHV6. 20/135 patients had SBI, and in 47/135, at least one virus was detected in the blood. Viremia had a higher sensitivity and negative predictive value (90% and 96%) to rule out SBI compared to CRP (65% and 93%) and PCT (55% and 90%). The odds ratio (OR) for the presence of SBI among non-viremic patients was 5.8 (p = 0.0225), compared to 5.5 for CRP ≥ 40 mg/l (p = 0.0009) and 3.7 for PCT ≥ 0.5 ng/mL (0.0093). This remained significant after adjusting for CRP and PCT (OR 5.6 and 5.9, respectively; p = 0.03 for both). Area under the ROC curve for CRP and PCT were 0.754 and 0.779, respectively, but increased to 0.803 and 0.832, respectively, when combined with viremia. CONCLUSION: The presence of viremia had a better performance than commonly used biomarkers to rule-out SBI and could potentially be used in conjunction with CRP and/or PCT in the evaluation of children with FWS. Larger studies should evaluate the role of point-of-care testing of viruses by (revere-transcription) PCR in the plasma in management algorithms of children with FWS. WHAT IS KNOWN: • Most children with FWS have a viral infection, but up to 15% have a SBI; most require laboratory tests, and many admission and empirical antibiotics. • Children with a viral infection are less likely to have a SBI. WHAT IS NEW: • Children with a systemic viral infection are less likely to have an SBI. • Viremia is a better predictor of absence of SBI than commonly used biomarkers and could potentially be used in conjunction with CRP and/or PCT in the evaluation of children with FWS.

First nosocomial infections in children supported by veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

BACKGROUND: Veno-arterial Extracorporeal Membrane Oxygenation (VA-ECMO) is a standard procedure for patient with refractory shock in Pediatric Intensive Care Unit (PICU). There is a paucity of data on the time relationship between VA-ECMO support, nosocomial infection occurrence, and PICU length of stay (LOS). The aim of this study was to determine the characteristics and impact of ECMO-related infections. METHODS: This is a retrospective study from 01/2008 to 12/2014, enrolling children with a VA-ECMO support for > 6 h. We recorded the first PICU infection during the VA-ECMO run, defined as a positive microbiological sample with clinical signs of infection or clinical signs of severe infection without positive sample. RESULTS: During the study period, 41 patients (25/41 male) were included, with a median age of 41.2 months (IQR 12.9-89.9) and a 53% mortality rate. Median time on VA-ECMO was 4.2 d (IQR 2-7.1), median PICU LOS was 14.7 d (IQR 4,7-26,9). Overall, 34% patients developed an infection, with an incidence of 60/1000 VA-ECMO days. Median time to first infection was 4 d (IQR 3-5), with Pseudomonas spp. being the most commonly detected microorganism (42%). Infected sites were ventilator-associated pneumonia (9/14), sternotomy infection (2/14), bloodstream (2/14) and urinary tract infections (1/14). Longer VA-ECMO support (> 5 d) (OR 5.9 (CI 95% 1.4-24.6; p = 0.01) and longer PICU stay (> 14 d) (OR 12 (95% CI 2.2-65.5; p = 0.004) were associated with infection. CONCLUSION: In this single-center study, we underlined the high proportion and early occurrence of infections in patient on VA-ECMO, mostly in the first week. As infection was an early event, it may prolong the duration of VA-ECMO support and PICU LOS. Further research is needed to better understand the impact of infections on VA-ECMO and develop prevention strategies.

The Development of a Chatbot Technology to Disseminate Post-COVID-19 Information: Descriptive Implementation Study.

BACKGROUND: Post-COVID-19, or long COVID, has now affected millions of individuals, resulting in fatigue, neurocognitive symptoms, and an impact on daily life. The uncertainty of knowledge around this condition, including its overall prevalence, pathophysiology, and management, along with the growing numbers of affected individuals, has created an essential need for information and disease management. This has become even more critical in a time of abundant online misinformation and potential misleading of patients and health care professionals. OBJECTIVE: The RAFAEL platform is an ecosystem created to address the information about and management of post-COVID-19, integrating online information, webinars, and chatbot technology to answer a large number of individuals in a time- and resource-limited setting. This paper describes the development and deployment of the RAFAEL platform and chatbot in addressing post-COVID-19 in children and adults. METHODS: The RAFAEL study took place in Geneva, Switzerland. The RAFAEL platform and chatbot were made available online, and all users were considered participants of this study. The development phase started in December 2020 and included developing the concept, the backend, and the frontend, as well as beta testing. The specific strategy behind the RAFAEL chatbot balanced an accessible interactive approach with medical safety, aiming to relay correct and verified information for the management of post-COVID-19. Development was followed by deployment with the establishment of partnerships and communication strategies in the French-speaking world. The use of the chatbot and the answers provided were continuously monitored by community moderators and health care professionals, creating a safe fallback for users. RESULTS: To date, the RAFAEL chatbot has had 30,488 interactions, with an 79.6% (6417/8061) matching rate and a 73.2% (n=1795) positive feedback rate out of the 2451 users who provided feedback. Overall, 5807 unique users interacted with the chatbot, with 5.1 interactions per user, on average, and 8061 stories triggered. The use of the RAFAEL chatbot and platform was additionally driven by the monthly thematic webinars as well as communication campaigns, with an average of 250 participants at each webinar. User queries included questions about post-COVID-19 symptoms (n=5612, 69.2%), of which fatigue was the most predominant query (n=1255, 22.4%) in symptoms-related stories. Additional queries included questions about consultations (n=598, 7.4%), treatment (n=527, 6.5%), and general information (n=510, 6.3%). CONCLUSIONS: The RAFAEL chatbot is, to the best of our knowledge, the first chatbot developed to address post-COVID-19 in children and adults. Its innovation lies in the use of a scalable tool to disseminate verified information in a time- and resource-limited environment. Additionally, the use of machine learning could help professionals gain knowledge about a new condition, while concomitantly addressing patients' concerns. Lessons learned from the RAFAEL chatbot will further encourage a participative approach to learning and could potentially be applied to other chronic conditions.

Autoantibodies against apolipoprotein A-1 after COVID-19 predict symptoms persistence.

BACKGROUND: SARS-CoV-2 infection triggers different auto-antibodies, including anti-apolipoprotein A-1 IgGs (AAA1), which could be of concern as mediators of persistent symptoms. We determined the kinetics of AAA1 response over after COVID-19 and the impact of AAA1 on the inflammatory response and symptoms persistence. METHODS: All serologies were assessed at one, three, six and twelve months in 193 hospital employees with COVID-19. ROC curve analyses and logistic regression models (LRM) were used to determine the prognostic accuracy of AAA1 and their association with patient-reported COVID-19 symptoms persistence at 12 months. Interferon (IFN)-α and-γ production by AAA1-stimulated human monocyte-derived macrophages (HMDM) was assessed in vitro. RESULTS: AAA1 seropositivity was 93% at one month and declined to 15% at 12 months after COVID-19. Persistent symptoms at 12 months were observed in 45.1% of participants, with a predominance of neurological (28.5%), followed by general (15%) and respiratory symptoms (9.3%). Over time, strength of correlations between AAA1 and anti-SARS-COV2 serologies decreased, but remained significant. From the 3rd month on, AAA1 levels predicted persistent respiratory symptoms (area under the curves 0.72-0.74; p < 0.001), independently of disease severity, age and gender (adjusted odds ratios 4.81-4.94; p = 0.02), while anti-SARS-CoV-2 serologies did not. AAA1 increased IFN-α production by HMDMs (p = 0.03), without affecting the IFN-γ response. CONCLUSION: COVID-19 induces a marked though transient AAA1 response, independently predicting one-year persistence of respiratory symptoms. By increasing IFN-α response, AAA1 may contribute to persistent symptoms. If and how AAA1 levels assessment could be of use for COVID-19 risk stratification remains to be determined.

Update on COVID-19 vaccination in pediatric solid organ transplant recipients.

BACKGROUND: COVID-19 vaccination has been successful in decreasing rates of SARS-CoV-2 infection in areas with high vaccine uptake. Cases of breakthrough SARS-CoV-2 infection remain infrequent among immunocompetent vaccine recipients who are protected from severe COVID-19. Robust data demonstrate the safety, immunogenicity, and effectiveness of several COVID-19 vaccine formulations. Importantly, Pfizer-BioNTech BNT162b2 mRNA COVID-19 vaccine studies have now included children as young as 5 years of age with safety, immunogenicity, and effectiveness data publicly available. In the United States, emergency use authorization by the Federal Drug Administration and approval from the Centers for Disease Control/Advisory Committee on Immunization Practices have been provided for the 5- to 11-year-old age group. METHODS: Members of the International Pediatric Transplant Association (IPTA) provide an updated review of current COVID-19 vaccine data with focus on pediatric solid organ transplant (SOT)-specific issues. RESULTS: This review provides an overview of current COVID-19 immunogenicity, safety, and efficacy data from key studies, with focus on data of importance to pediatric SOT recipients. Continued paucity of data in the setting of pediatric transplantation remains a challenge. CONCLUSIONS: Further studies of COVID-19 vaccination in pediatric SOT recipients are needed to better understand post-vaccine COVID-19 T-cell and antibody kinetics and determine the optimal vaccine schedule. Increased COVID-19 vaccine acceptability, uptake, and worldwide availability are needed to limit the risk that COVID-19 poses to pediatric solid organ transplant recipients.

Prevalence of Immunoglobulin G (IgG) Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Evaluation of a Rapid MEDsan IgG Test in Children Seeking Medical Care.

In 208 children seeking medical care, the seropositivity rate of anti-SARS-CoV-2 IgG antibodies was 8.7%, suggesting an infection rate similar to that observed in adults but >100-fold the incidence of RT-PCR-confirmed pediatric cases. Compared with the gold-standard combined ELISA + immunofluorescence, the MEDsan IgG rapid diagnostic test performed accurately.

Seroprevalence of anti-SARS-CoV-2 IgG antibodies in Geneva, Switzerland (SEROCoV-POP): a population-based study.

BACKGROUND: Assessing the burden of COVID-19 on the basis of medically attended case numbers is suboptimal given its reliance on testing strategy, changing case definitions, and disease presentation. Population-based serosurveys measuring anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) antibodies provide one method for estimating infection rates and monitoring the progression of the epidemic. Here, we estimate weekly seroprevalence of anti-SARS-CoV-2 antibodies in the population of Geneva, Switzerland, during the epidemic. METHODS: The SEROCoV-POP study is a population-based study of former participants of the Bus Santé study and their household members. We planned a series of 12 consecutive weekly serosurveys among randomly selected participants from a previous population-representative survey, and their household members aged 5 years and older. We tested each participant for anti-SARS-CoV-2-IgG antibodies using a commercially available ELISA. We estimated seroprevalence using a Bayesian logistic regression model taking into account test performance and adjusting for the age and sex of Geneva's population. Here we present results from the first 5 weeks of the study. FINDINGS: Between April 6 and May 9, 2020, we enrolled 2766 participants from 1339 households, with a demographic distribution similar to that of the canton of Geneva. In the first week, we estimated a seroprevalence of 4·8% (95% CI 2·4-8·0, n=341). The estimate increased to 8·5% (5·9-11·4, n=469) in the second week, to 10·9% (7·9-14·4, n=577) in the third week, 6·6% (4·3-9·4, n=604) in the fourth week, and 10·8% (8·2-13·9, n=775) in the fifth week. Individuals aged 5-9 years (relative risk [RR] 0·32 [95% CI 0·11-0·63]) and those older than 65 years (RR 0·50 [0·28-0·78]) had a significantly lower risk of being seropositive than those aged 20-49 years. After accounting for the time to seroconversion, we estimated that for every reported confirmed case, there were 11·6 infections in the community. INTERPRETATION: These results suggest that most of the population of Geneva remained uninfected during this wave of the pandemic, despite the high prevalence of COVID-19 in the region (5000 reported clinical cases over <2·5 months in the population of half a million people). Assuming that the presence of IgG antibodies is associated with immunity, these results highlight that the epidemic is far from coming to an end by means of fewer susceptible people in the population. Further, a significantly lower seroprevalence was observed for children aged 5-9 years and adults older than 65 years, compared with those aged 10-64 years. These results will inform countries considering the easing of restrictions aimed at curbing transmission. FUNDING: Swiss Federal Office of Public Health, Swiss School of Public Health (Corona Immunitas research program), Fondation de Bienfaisance du Groupe Pictet, Fondation Ancrage, Fondation Privée des Hôpitaux Universitaires de Genève, and Center for Emerging Viral Diseases.

COVID-19 vaccination in pediatric solid organ transplant recipients-Current state and future directions.

BACKGROUND: Population-level COVID-19 immunization will play a key role in slowing down the SARS-CoV-2 pandemic on a global scale and protect the most at-risk individuals. Thanks to a formidable universal effort, several SARS-CoV-2 vaccines have been marketed less than a year since the first documented COVID-19 case, with promising safety, efficacy, and immunogenicity results in adults. As children were not included in the initial trials, no vaccine is currently approved for individuals <16 years of age. Similarly, immunosuppressed individuals, such as solid organ transplant recipients, were excluded from initial vaccine trials, limiting the understanding of vaccine immunogenicity and safety in this at-risk population. Thus, data regarding COVID-19 vaccination in pediatric solid organ transplantation recipients are currently lacking. METHODS: Members of the International Pediatric Transplant Association review the current general status of COVID-19 vaccines focusing on pediatric-specific issues. RESULTS: This review provides an overview of COVID-19 vaccines in pediatric SOT recipients and highlights the current paucity of data in both pediatric and transplant settings in terms of safety, immunogenicity, and clinical efficacy. CONCLUSIONS: Vaccine trials including children and transplant recipients are underway and will be necessary to characterize COVID-19 vaccine safety, immunogenicity, and efficacy, which will determine potential future research directions.

SARS-CoV-2 and pediatric solid organ transplantation: Current knowns and unknowns.

The COVID-19 pandemic has proven to be a challenge in regard to the clinical presentation, prevention, diagnosis, and management of SARS-CoV-2 infection among children who are candidates for and recipients of SOT. By providing scenarios and frequently asked questions encountered in routine clinical practice, this document provides expert opinion and summarizes the available data regarding the prevention, diagnosis, and management of SARS-CoV-2 infection among pediatric SOT candidates and recipients and highlights ongoing knowledge gaps requiring further study. Currently available data are still lacking in the pediatric SOT population, but data have emerged in both the adult SOT and general pediatric population regarding the approach to COVID-19. The document provides expert opinion regarding prevention, diagnosis, and management of SARS-CoV-2 infection among pediatric SOT candidates and recipients.

Risk of Vaccine-Preventable Infections in Swiss Adults with Inflammatory Bowel Disease.

BACKGROUND: Patients with inflammatory bowel disease (IBD) have a higher risk of infection and are frequently not up to date with their immunizations. OBJECTIVES: This study aims to review vaccination status and evaluate whether age, disease type, or treatment regimen could predict the absence of seroprotection against selected vaccine-preventable infection in adults with IBD. METHODS: Cross-sectional study using questionnaire, immunization records review, and assessment of tetanus-specific, varicella-specific, and measles-specific immunoglobulin G concentrations. ClinicalTrials.gov: NCT01908283. RESULTS: Among the 306 adults assessed (median age 42.7 years old, 70% with Crohn's disease, 78% receiving immunosuppressive treatment), only 33% had an immunization record available. Absence of seroprotection against tetanus (6%) was associated with increasing age and absence of booster dose; absence of seroprotection against varicella (1%) or measles (3%) was exclusively observed in younger patients with Crohn's disease. There was no statistically significant difference in immunoglobulin concentrations among treatment groups. Although vaccinations are strongly recommended in IBD patients, the frequencies of participants with at least 1 dose of vaccine recorded were low for nearly all antigens: tetanus 94%, diphtheria 87%, pertussis 54%, poliovirus 22%, measles-mumps-rubella 47%, varicella-zoster 0%, Streptococcus pneumoniae 5%, Neisseria meningitidis 12%, hepatitis A 41%, hepatitis B 48%, human papillomavirus 5%, and tick-borne encephalitis 6%. CONCLUSIONS: Although many guidelines recommend the vaccination of IBD patients, disease prevention through immunization is still often overlooked, including in Switzerland, increasing their risk of vaccine-preventable diseases. Serological testing should be standardized to monitor patients' protection during follow-up as immunity may wane faster in this population.

Vaccination of immune compromised children-an overview for physicians.

Immune compromised children are threatened by a higher risk of infections; some of these are preventable by vaccination. Primary care physicians play a fundamental role in optimising vaccination status. In this narrative review, we present the evidence on vaccine safety and immunogenicity in immune compromised children and discuss in which conditions live-attenuated vaccines can possibly be used. Vaccination schedules differ in some of these conditions, including the use of vaccines with higher antigenic contents (e.g. high-dose hepatitis B vaccine), additional vaccine doses (e.g. 2-dose schedule meningococcal vaccine), more frequent booster doses (e.g. life-long pneumococcal vaccine booster), supplementary vaccines (e.g. meningococcal B vaccine) and use of vaccines beyond the age of usual recommendation (e.g. Haemophilus influenza type b vaccine after 5 years of age). Serological monitoring is a useful tool for customizing vaccination schedule in immune compromised children, confirming adequate vaccine response and documenting seroprotection (especially against measles and varicella). Finally, verification of vaccination status of all household members can prevent them being vector of transmission of an infection to the immune compromised children. Conclusion: Intensified information strategies are needed to improve trust, rectify perceived risks and improve vaccine acceptability; primary physicians can play a critical role in the latter. What is Known: • Physician's awareness is key to success, since it repeatedly correlates with higher vaccination rates What is New: • The vaccination status of immunocompromised children is rarely up-to-date • Knowing the latest vaccine recommendations is challenging, as they differ for each medical condition and change periodically • This review summarises the vaccine recommendations for children with compromised immune systems and highlights how paediatricians play a key role in coordinating their application.

Hypovitaminosis D in migrant children in Switzerland: a retrospective study.

Cholecalciferol (vitamin D3) is essentially known for its role in the phosphocalcic metabolism and its associated pathologies, such as rickets. In Switzerland, 35 to 50% of children are vitamin D deficient. Due to skin colour, poor nutrition, living conditions and cultural practices, migrant population is particularly at risk. Our aim is to attest the prevalence of hypovitaminosis D in children arriving in Switzerland. We retrospectively assessed 528 children's vitamin D status and parathyroid hormone, phosphate and calcium levels between 2015 and 2018 by electrochemiluminescence and spectrophotometry. Cholecalciferol was considered insufficient under 50 nmol/L and severely deficient below 25 nmol/L. Seventy-three percent of children showed hypovitaminosis D and 28% had a severe deficiency. Highest prevalence of deficiency was found in children from Eastern Mediterranean (80%) and African regions (75%). Severe deficiency was more prevalent in the South East Asian (39%) and Eastern Mediterranean regions (33%) and more frequent in females. Deficiency was more frequent and more severe in winter. Hypovitaminosis D increased with age. Two children presented with all three biological manifestations associated to severe hypovitaminosis D (hyperparathyroidism, hypocalcaemia and hypophosphatemia).Conclusion: A majority of migrant children presented with hypovitaminosis D. They should be supplemented to prevent complications. A strategy could be to supplement all children at arrival and during wintertime without regular vitamin D level checks. What is Known: Hypovitaminosis D is frequent in children and can lead to bone-related complications. Migrant children are particularly at risk of deficiency. What is New: Three-quarters of migrant children evaluated at our migrant clinic in Geneva's children hospital are deficient in vitamin D, one third severely. A strategy to correct the deficiency would be to supplement all migrant children at arrival and in winter.

Viral co-infections among SARS-CoV-2-infected children and infected adult household contacts.

We evaluated the rates of viral respiratory co-infections among SARS-CoV-2-infected children. Twelve percent of SARS-CoV-2-infected children had viral co-infection with one or more common respiratory viruses. This was significantly more frequent than among their SARS-CoV-2-infected adult household contacts (0%; p=0.028). Compared to the same period the previous year, common respiratory viruses were less frequently detected (12% vs 73%, p<0.001).Conclusion: Despite partial lockdown with school and daycare closure, and consequently similar exposure to common viruses between children and adults, SARS-CoV-2-infected children had more frequent viral respiratory co-infections than their SARS-CoV-2-infected adult household contacts. Circulation of common respiratory viruses was less frequent during the SARS-CoV-2 outbreak when compared to the same period last year, showing the impact of partial lockdown on the circulation of common viruses. What is Known: • Viral respiratory co-infections are frequent in children. • SARS-CoV-2 can be identified alongside other respiratory viruses, but data comparing children and adults are lacking. What is New: • Children infected with SARS-CoV-2 are more likely to have viral respiratory co-infections than their SARS-CoV-2-infected adult household contacts, which is surprising in the context of partial lockdown with schools and daycare closed. • When compared to data collected during the same period last year, our study also showed that partial lockdown reduced circulation of common respiratory viruses.

Swiss consensus recommendations on urinary tract infections in children.

The kidneys and the urinary tract are a common source of infection in children of all ages, especially infants and young children. The main risk factors for sequelae after urinary tract infections (UTI) are congenital anomalies of the kidney and urinary tract (CAKUT) and bladder-bowel dysfunction. UTI should be considered in every child with fever without a source. The differentiation between upper and lower UTI is crucial for appropriate management. Method of urine collection should be based on age and risk factors. The diagnosis of UTI requires urine analysis and significant growth of a pathogen in culture. Treatment of UTI should be based on practical considerations regarding age and presentation with adjustment of the initial antimicrobial treatment according to antimicrobial sensitivity testing. All children, regardless of age, should have an ultrasound of the urinary tract performed after pyelonephritis. In general, antibiotic prophylaxis is not recommended.Conclusion: Based on recent data and in line with international guidelines, multidisciplinary Swiss consensus recommendations were developed by members of Swiss pediatric infectious diseases, nephrology, and urology societies giving the clinician clear recommendations in regard to diagnosis, type and duration of therapy, antimicrobial treatment options, indication for imaging, and antibiotic prophylaxis. What is Known: • Urinary tract infections (UTI) are a common and important clinical problem in childhood. Although children with pyelonephritis tend to present with fever, it can be difficult on clinical grounds to distinguish cystitis from pyelonephritis, particularly in young children less than 2 years of age. • Method of urine collection is based on age and risk factors. The diagnosis of UTI requires urine analysis and significant growth of a pathogen in culture. What is New: • Vesicoureteric reflux (VUR) remains a risk factor for UTI but per se is neither necessary nor sufficient for the development of renal scars. Congenital anomalies of the kidney and urinary tract (CAKUT) and bladder-bowel dysfunction play a more important role as causes of long-term sequelae. In general, antibiotic prophylaxis is not recommended. • A switch to oral antibiotics should be considered already in young infants. Indications for invasive imaging are more restrictive and reserved for patients with abnormal renal ultrasound, complicated UTI, and infections with pathogens other than E. coli.

Seroprevalence of anti-SARS-CoV-2 antibodies 6 months into the vaccination campaign in Geneva, Switzerland, 1 June to 7 July 2021.

BackgroundUp-to-date seroprevalence estimates are critical to describe the SARS-CoV-2 immune landscape and to guide public health decisions.AimWe estimate seroprevalence of anti-SARS-CoV-2 antibodies 15 months into the COVID-19 pandemic and 6 months into the vaccination campaign.MethodsWe conducted a population-based cross-sectional serosurvey between 1 June and 7 July 2021, recruiting participants from age- and sex-stratified random samples of the general population. We tested participants for anti-SARS-CoV-2 antibodies targeting the spike (S) or nucleocapsid (N) proteins using the Roche Elecsys immunoassays. We estimated the anti-SARS-CoV-2 antibodies seroprevalence following vaccination and/or infection (anti-S antibodies), or infection only (anti-N antibodies).ResultsAmong 3,355 individuals (54.1% women; 20.8% aged < 18 years and 13.4% aged ≥ 65 years), 2,161 (64.4%) had anti-S antibodies and 906 (27.0%) had anti-N antibodies. The total seroprevalence was 66.1% (95% credible interval (CrI): 64.1-68.0). We estimated that 29.9% (95% Crl: 28.0-31.9) of the population developed antibodies after infection; the rest having developed antibodies via vaccination. Seroprevalence estimates differed markedly across age groups, being lowest among children aged 0-5 years (20.8%; 95% Crl: 15.5-26.7) and highest among older adults aged ≥ 75 years (93.1%; 95% Crl: 89.6-96.0). Seroprevalence of antibodies developed via infection and/or vaccination was higher among participants with higher educational level.ConclusionMost of the population has developed anti-SARS-CoV-2 antibodies, despite most teenagers and children remaining vulnerable to infection. As the SARS-CoV-2 Delta variant spreads and vaccination rates stagnate, efforts are needed to address vaccine hesitancy, particularly among younger individuals and to minimise spread among children.