SARS-CoV-2 infection in pediatric population before and during the Delta (B.1.617.2) and Omicron (B.1.1.529) variants era

Dynamic of SARS-CoV-2 variants circulation in Tunisian pediatric population, during successive waves, from March 2020 to September 2022

The emergence of SARS-CoV-2 variants has led to several cases among children. However, limited information is available from North African countries. This study describes the SARS-CoV-2 strains circulating in Tunisian pediatric population during successive waves. A total of 447 complete sequences were obtained from individuals aged from 13 days to 18 years, between March 2020 and September 2022: 369 sequences generated during this study and 78 ones, available in GISAID, previously obtained from Tunisian pediatric patients. These sequences were compared with 354 and 274 ones obtained from Tunisian adults and a global dataset, respectively. The variant circulation dynamics of predominant variants were investigated during the study period using maximum-likelihood phylogenetic analysis. Among the studied population, adolescents were the predominant age group, comprising 55.26% of cases. Twenty-three lineages were identified; seven of which were not previously reported in Tunisia. Phylogenetic analysis showed a close relationship between the sequences from Tunisian adults and children. The connections of sequences from other countries were variable according to variants: close relationships were observed for Alpha, B1.160 and Omicron variants, while independent Tunisian clusters were observed for Delta and B.1.177 lineages. These findings highlight the pivotal role of children in virus transmission and underscore the impact of vaccination on virus spread. Vaccination of children, with booster doses, may be considered for better management of future emergences.

SARS-CoV-2 Disease Severity and Cycle Threshold Values in Children Infected during Pre-Delta, Delta, and Omicron Periods, Colorado, USA, 2021-2022

In adults, viral load and disease severity can differ by SARS-CoV-2 variant, patterns less understood in children. We evaluated symptomatology, cycle threshold (Ct) values, and SARS-CoV-2 variants among 2,299 pediatric SARS-CoV-2 patients (0-21 years of age) in Colorado, USA, to determine whether children infected with Delta or Omicron had different symptom severity or Ct values than during earlier variants. Children infected during the Delta and Omicron periods had lower Ct values than those infected during pre-Delta, and children <1 year of age had lower Ct values than older children. Hospitalized symptomatic children had lower Ct values than asymptomatic patients. Compared with pre-Delta, more children infected during Delta and Omicron were symptomatic (75.4% pre-Delta, 95.3% Delta, 99.5% Omicron), admitted to intensive care (18.8% pre-Delta, 39.5% Delta, 22.9% Omicron), or received oxygen support (42.0% pre-Delta, 66.3% Delta, 62.3% Omicron). Our data reinforce the need to include children, especially younger children, in pathogen surveillance efforts.

COVID-19 Vaccines in the Pediatric Population: A Focus on Cardiac Patients

Due to the deleterious global impact of the COVID-19 pandemic, tremendous effort has been invested in the development of vaccines against the virus. Vaccine candidates are first tested in adult populations, a number of which have been approved for EUL by the WHO, and are in use across the USA and MENA region. The question remains whether these (or other) vaccines should be recommended to a neonatal, pediatric, and/or adolescent cohort. Incidence and severity of COVID-19 infection are low in pediatric, neonatal, and adolescent patients. Since both overall incidence and severity are lower in children than in adults, safety is an important consideration in vaccine approval for these age groups, in addition to efficacy and a decreased risk of transmission. The following review discusses vaccine immunology in children aged 0-18 years, with emphasis on the negative impact of the COVID-19 pandemic on the lives of children, considerations for pediatric vaccine approval, and available vaccines for pediatric cohorts along with a breakdown of the efficacy, advantages, and disadvantages for each. This review also contains current and future perspectives, as well as a section on the cardiovascular implications and related dynamics of pediatric COVID-19 vaccination.

Clinical manifestations and long-term symptoms associated with SARS-CoV-2 omicron infection in children aged 0-17 years in Beijing: a single-center study

Objective

The study aims to analyze the clinical characteristics of acute phase of SARS-CoV-2 infection in children aged 0-17 years with the Omicron variant, and summarize the persistent symptoms or new-onset clinical manifestations from 4 to 12 weeks after acute COVID. Explore the association between the vaccination status and SARS-CoV-2 neutralizing antibody levels post infection among preschool-aged children. The comprehensive study systematically describes the clinical characteristics of children infected with SARS-CoV-2, providing a foundation for diagnosis and evaluating long-term COVID in pediatric populations.

Methods

The study enrolled children who were referred to the Children's Hospital, Capital Institute of Pediatrics, (Beijing, China) from January 10, 2023 to March 31, 2023. Participants were classified as infant and toddlers, preschool, school-age, and adolescent groups. Children or their legal guardians completed survey questionnaires to provide information of previous SARS-CoV-2 infection history, as well as clinical presentation during the acute phase and long-term symptoms from 4 to 12 weeks following infection. Furthermore, serum samples were collected from children with confirmed history of SARS-CoV-2 infection for serological testing of neutralizing antibodies.

Results

The study recruited a total of 2,001 children aged 0-17 years who had previously tested positive for SARS-CoV-2 through nucleic acid or antigen testing. Fever emerged as the predominant clinical manifestation in 1,902 (95.1%) individuals with body temperature ranging from 37.3 to 40.0°C. Respiratory symptoms were identified as secondary clinical manifestations, with cough being the most common symptom in 777 (38.8%) children, followed by sore throat (22.1%), nasal congestion (17.8%), and runnning nose (17.2%). Fatigue (21.6%), headache (19.8%) and muscle-joint pain (13.5%) were frequently reported systemic symptoms in children. The proportion of children with symptoms of SARS-CoV-2 infection varied across age groups. 1,100 (55.0%) children experienced persistent symptoms from 4 to 12 weeks post the acute phase of infection. Trouble concentrating (22.1%), cough (22.1%), and fatigue (12.1%) were frequently reported across age groups in the extended period. A limited number of children exhibited cardiovascular symptoms with chest tightness, tachycardia, and chest pain reported by 3.5%, 2.5%, and 1.8% of children, respectively. Among 472 children aged 3-5 years, 208 children had received two doses of SARS-CoV-2 vaccine at least 6 months prior to infection, and no association was found between the incidence of long-term COVID and pre-infection vaccination statuses among the 3-5 years age groups (χ2 = 1.136, P = 0.286).

Conclusions

In children aged 0-17 years infected with SARS-CoV-2 Omicron variant, fever was the primary clinical manifestation in the acute phase, followed by respiratory symptoms, systemic non-specific and digestive presentations. In particular, respiratory and digestive system symptoms were more frequent in children aged above 6 years. Regarding the long-term symptoms from 4 to 12 weeks post-infection, the most common presentations were concentrating difficulty, cough, and fatigue. The incidence of persistent symptoms of SARS-CoV-2 did not exhibit a significant correlation with vaccination status, which was attributed to the waning efficacy of the vaccine-induced humoral immune response after 6 months.

Seroprevalence of SARS-CoV-2 in self-reported COVID-19-free children

INTRODUCTION

COVID-19 poses risks and leads to complications for vulnerable populations, including children. Unreported cases of COVID-19 among children hinder our understanding of the true disease burden. In this study, we aimed to investigate the proportion of children who report no prior infection to SARS-CoV-2 but who nevertheless exhibit serological evidence of prior infection.

METHODS

Between November 2022 and February 2023, we recruited children and adolescents under 19 years of age who lacked a prior history of SARS-CoV-2 infection. Participants underwent SARS-CoV-2 antibody testing to assess the presence of IgG antibodies specific to nucleocapsid (N) and spike (S) proteins. Demographic and contact information were also collected.

RESULTS

Among 260 COVID-19-free children, the overall anti-N antibody positivity rate, which varied across age groups (4%-25%), was 9.2% (24/260). Contact with individuals who were positive for COVID-19, particularly the children's mothers, significantly increased the likelihood of antibody positivity. The median age of the 34 children who remained unvaccinated against COVID-19 was lower than that of the children who were vaccinated (6.5 vs. 9 years; p < 0.001). Until January 2024, the overall infection rate was 41.9% (99/236) among children who were negative for anti-N antibodies, irrespective of vaccination status or the presence of chronic disease.

CONCLUSION

We discovered previously undisclosed cases of SARS-CoV-2 infection among children. The risk of seropositivity increases substantially with household contact. Regarding children who report no prior exposure to COVID-19, clinicians must remain vigilant, as SARS-CoV-2 remains a concern.

Long-term monitoring of SARS-CoV-2 variants in wastewater using a coordinated workflow of droplet digital PCR and nanopore sequencing

Quantitative polymerase chain reaction (PCR) and genome sequencing are important methods for wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The reverse transcription-droplet digital PCR (RT-ddPCR) is a highly sensitive method for quantifying SARS-CoV-2 RNA in wastewater samples to track the trends of viral activity levels but cannot identify new variants. It also takes time to develop new PCR-based assays targeting variants of interest. Whole genome sequencing (WGS) can be used to monitor known and new SARS-CoV-2 variants, but it is generally not quantitative. Several short-read sequencing techniques can be expensive and might experience delayed turnaround times when outsourced due to inadequate in-house resources. Recently, a portable nanopore sequencing system offers an affordable and real-time method for sequencing SARS-CoV-2 variants in wastewater. This technology has the potential to enable swift response to disease outbreaks without relying on clinical sequencing results. In addressing concerns related to rapid turnaround time and accurate variant analysis, both RT-ddPCR and nanopore sequencing methods were employed to monitor the emergence of SARS-CoV-2 variants in wastewater. This surveillance was conducted at 23 sewer maintenance hole sites and five wastewater treatment plants in Michigan from 2020 to 2022. In 2020, the wastewater samples were dominated by the parental variants (20A, 20C and 20 G), followed by 20I (Alpha, B.1.1.7) in early 2021 and the Delta variant of concern (VOC) in late 2021. For the year 2022, Omicron variants dominated. Nanopore sequencing has the potential to validate suspected variant cases that were initially undetermined by RT-ddPCR assays. The concordance rate between nanopore sequencing and RT-ddPCR assays in identifying SARS-CoV-2 variants to the clade-level was 76.9%. Notably, instances of disagreement between the two methods were most prominent in the identification of the parental and Omicron variants. We also showed that sequencing wastewater samples with SARS-CoV-2 N gene concentrations of >104 GC/100 ml as measured by RT-ddPCR improve genome recovery and coverage depth using MinION device. RT-ddPCR was better at detecting key spike protein mutations A67V, del69-70, K417N, L452R, N501Y, N679K, and R408S (p-value <0.05) as compared to nanopore sequencing. It is suggested that RT-ddPCR and nanopore sequencing should be coordinated in wastewater surveillance where RT-ddPCR can be used as a preliminary quantification method and nanopore sequencing as the confirmatory method for the detection of variants or identification of new variants. The RT-ddPCR and nanopore sequencing methods reported here can be adopted as a reliable in-house analysis of SARS-CoV-2 in wastewater for rapid community level surveillance and public health response.

SARS-CoV-2 variant of concern fitness and adaptation in primary human airway epithelia

The severe acute respiratory syndrome coronavirus 2 pandemic is characterized by the emergence of novel variants of concern (VOCs) that replace ancestral strains. Here, we dissect the complex selective pressures by evaluating variant fitness and adaptation in human respiratory tissues. We evaluate viral properties and host responses to reconstruct forces behind D614G through Omicron (BA.1) emergence. We observe differential replication in airway epithelia, differences in cellular tropism, and virus-induced cytotoxicity. D614G accumulates the most mutations after infection, supporting zoonosis and adaptation to the human airway. We perform head-to-head competitions and observe the highest fitness for Gamma and Delta. Under these conditions, RNA recombination favors variants encoding the B.1.617.1 lineage 3' end. Based on viral growth kinetics, Alpha, Gamma, and Delta exhibit increased fitness compared to D614G. In contrast, the global success of Omicron likely derives from increased transmission and antigenic variation. Our data provide molecular evidence to support epidemiological observations of VOC emergence.

The effectiveness of the COVID-19 vaccines in the prevention of post-COVID conditions in children and adolescents: a systematic literature review and meta-analysis

Objective

We performed a systematic literature review and meta-analysis on the effectiveness of coronavirus disease 2019 (COVID-19) vaccination against post-COVID conditions (long COVID) in the pediatric population.

Design

Systematic literature review/meta-analysis.

Methods

We searched PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMBASE, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science from December 1, 2019, to August 14, 2023, for studies evaluating the COVID-19 vaccine effectiveness against post-COVID conditions among vaccinated individuals < 21 years old who received at least 1 dose of COVID-19 vaccine. A post-COVID condition was defined as any symptom that was present 4 or more weeks after COVID-19 infection. We calculated the pooled diagnostic odds ratio (DOR) (95% CI) for post-COVID conditions between vaccinated and unvaccinated individuals.

Results

Eight studies with 23,995 individuals evaluated the effect of vaccination on post-COVID conditions, of which 5 observational studies were included in the meta-analysis. The prevalence of children who did not receive COVID-19 vaccines ranged from 65% to 97%. The pooled prevalence of post-COVID conditions was 21.3% among those unvaccinated and 20.3% among those vaccinated at least once. The pooled DOR for post-COVID conditions among individuals vaccinated with at least 1 dose and those vaccinated with 2 doses were 1.07 (95% CI, 0.77-1.49) and 0.82 (95% CI, 0.63-1.08), respectively.

Conclusions

A significant proportion of children and adolescents were unvaccinated, and the prevalence of post-COVID conditions was higher than reported in adults. While vaccination did not appear protective, conclusions were limited by the lack of randomized trials and selection bias inherent in observational studies.

Impact of COVID-19 on the Pediatric Primary Care Model in Catalonia: Analysis of Changes in the Number and Type of Face-to-Face and Remote Visits

Background

The outbreak of COVID-19 has turned the care model of health systems around the world upside down. The health care crisis has led to opportunities for digital health to deliver quality care, and the system has been redirected toward telemedicine. In Catalonia, Spain, as of March 2020, the pattern of visits in primary care pediatric consultations changed, such that face-to-face visits decreased in favor of non-face-to-face visits.

Objective

This study aimed to analyze variations in the types of pediatric visits in primary care centers in Catalonia before and after the onset of COVID-19.

Methods

This was a descriptive observational study based on administrative data. The number and type of visits to primary care pediatric services in Catalonia between January 2019 and December 2022 were studied.

Results

A drop of more than 80% in face-to-face visits and an increase of up to 15 times in remote visits were observed as of March 2020 compared to the previous year. Subsequently, the face-to-face attendance rate began to recover, although it did not reach the same rate as before COVID-19. Non-face-to-face visits were maintained, representing more than 20% of the total after more than 2 years of the pandemic.

Conclusions

COVID-19 has been the trigger for a transition in the types of visits to primary care pediatric services. The COVID-19 pandemic was a clear catalyst for the integration of telemedicine in Catalan pediatric health care. In this context, although face-to-face consultations have recovered in absolute numbers, after the pandemic period, the weight of telemedicine has increased.

Outcomes of Extracorporeal Life Support Utilization for Pediatric Patients With COVID-19 Infections

Outcomes of pediatric patients who received extracorporeal life support (ECLS) for COVID-19 remain poorly described. The aim of this multi-institutional retrospective observational study was to evaluate these outcomes and assess for prognostic factors associated with in-hospital mortality. Seventy-nine patients at 14 pediatric centers across the United States who received ECLS support for COVID-19 infections between January 2020 and July 2022 were included for analysis. Data were extracted from the electronic medical record. The median age was 14.5 years (interquartile range [IQR]: 2-17 years). Most patients were female (54.4%) and had at least one pre-existing comorbidity (84.8%), such as obesity (44.3%, median body mass index percentile: 97% [IQR: 67.5-99.0%]). Venovenous (VV) ECLS was initiated in 50.6% of patients. Median duration of ECLS was 12 days (IQR: 6.0-22.5 days) with a mean duration from admission to ECLS initiation of 5.2 ± 6.3 days. Survival to hospital discharge was 54.4%. Neurological deficits were reported in 16.3% of survivors. Nonsurvivors were of older age (13.3 ± 6.2 years vs. 9.3 ± 7.7 years, p  = 0.012), more likely to receive renal replacement therapy (63.9% vs. 30.2%, p  = 0.003), demonstrated longer durations from admission to ECLS initiation (7.0 ± 8.1 days vs. 3.7 ± 3.8 days, p  = 0.030), and had higher rates of ECLS-related complications (91.7% vs. 69.8%, p  = 0.016) than survivors. Pediatric patients with COVID-19 who received ECLS demonstrated substantial morbidity and further investigation is warranted to optimize management strategies.

Old foes following news ways?-Pandemic-related changes in the epidemiology of viral respiratory tract infections

INTRODUCTION

Following lockdown periods and restricting public health measures in response to the COVID-19 pandemic, respiratory tract infections (RTIs) rose significantly worldwide. This led to an increased burden on children's hospitals compromising medical care of acutely and chronically ill children. We characterized changes in the epidemiological pattern of circulating respiratory viral infections.

METHODS

We assessed the number of patients with RTIs and the annual distribution of virus detections between 2019 and 2022 based on 4809 clinical samples (4131 patients) from a German pediatric tertiary care-center. We investigated the impact of lockdown periods on spectra of circulating respiratory viruses, pattern of coinfections, age, and seasonality of infections.

RESULTS

A fourfold increase in the number of respiratory virus detections was observed in 2022 vs 2019 with numbers doubling in 2022 (vs 2021). In 2022, seasonal patterns of circulating virus, particularly Adeno and seasonal Coronavirus were far less pronounced compared to previous years, in fact almost disappeared for Rhinoviruses.". SARS-CoV-2, Parainfluenza- and human Metapneumovirus detections increased significantly in 2022 (2019 vs 2022, p < 0.01). Coinfections with multiple viruses occurred more frequently since 2021 compared to pre-pandemic years, especially in younger children (2019 vs 2022, p < 0.01).

CONCLUSION

Compared to pre-pandemic years, we observed a dramatic increase in pediatric RTIs with an incrementing spectrum of viruses and a predominance in Rhino/Enterovirus infections - leading to a high rate of hospital admissions, particularly in conjunction with other viruses. This caused an acute shortage in medical care and may also be followed by an increase of virus-triggered secondary chronic respiratory diseases like asthma-rendering a burden on the health system.

Risk Factors for Community and Intrahousehold Transmission of SARS-CoV-2: Modeling in a Nationwide French Population-Based Cohort Study, the EpiCoV Study

We assessed the risk of acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from household and community exposure according to age, family ties, and socioeconomic and living conditions using serological data from a nationwide French population-based cohort study, the Epidémiologie et Conditions de Vie (EpiCoV) Study. A history of SARS-CoV-2 infection was defined by a positive anti-SARS-CoV-2 enzyme-linked immunosorbent assay immunoglobulin G result in November-December 2020. We applied stochastic chain binomial models fitted to the final distribution of household infections to data from 17,983 individuals aged ≥6 years from 8,165 households. Models estimated the competing risks of being infected from community and household exposure. The age group 18-24 years had the highest risk of extrahousehold infection (8.9%, 95% credible interval (CrI): 7.5, 10.4), whereas the oldest (≥75 years) and youngest (6-10 years) age groups had the lowest risk, at 2.6% (95% CrI: 1.8, 3.5) and 3.4% (95% CrI: 1.9, 5.2), respectively. Extrahousehold infection was also associated with socioeconomic conditions. Within households, the probability of person-to-person transmission increased with age, from 10.6% (95% CrI: 5.0, 17.9) among children aged 6-10 years to 43.1% (95% CrI: 32.6, 53.2) among adults aged 65-74 years. Transmission was higher between partners (29.9%, 95% CrI: 25.6, 34.3) and from mother to child (29.1%, 95% CrI: 21.4, 37.3) than between individuals related by other family ties. In 2020 in France, the main factors identified for extrahousehold SARS-CoV-2 infection were age and socioeconomic conditions. Intrahousehold infection mainly depended on age and family ties.

Genomic Surveillance of SARS-CoV-2 Sequence Variants at Universities in Southwest Idaho

Although the impact of the SARS-CoV-2 pandemic on major metropolitan areas is broadly reported and readily available, regions with lower populations and more remote areas in the United States are understudied. The objective of this study is to determine the progression of SARS-CoV-2 sequence variants in a frontier and remote intermountain west state among university-associated communities. This study was conducted at two intermountain west universities from 2020 to 2022. Positive SARS-CoV-2 samples were confirmed by quantitative real-time reverse transcription-polymerase chain reaction and variants were identified by the next-generation sequencing of viral genomes. Positive results were obtained for 5355 samples, representing a positivity rate of 3.5% overall. The median age was 22 years. Viral genomic sequence data were analyzed for 1717 samples and phylogeny was presented. Associations between viral variants, age, sex, and reported symptoms among 1522 samples indicated a significant association between age and the Delta variant (B 1.167.2), consistent with the findings for other regions. An outbreak event of AY122 was detected August-October 2021. A 2-month delay was observed with respect to the timing of the first documented viral infection within this region compared to major metropolitan regions of the US.

A descriptive study on the potential transmission of COVID-19 to hospitalized patients from a nursery school affiliated with it

INTRODUCTION

During the epidemic of the Omicron variant of SARS-CoV-2, nosocomial transmissions from healthcare workers (HCWs) to patients occur frequently. The influence of COVID-19 on hospitalized patients from nursing schools affiliated with the hospitals is a concern but it had not been well studied.

METHODS

We here describe COVID-19 outbreaks at the nursery school affiliated with an acute-care hospital, during the surges of the Omicron variants on the transmission of SARS-CoV-2 children as well as for the patients who were judged to be the close contacts of patients of COVID-19 by contact investigation by PCR testing.

RESULTS

A total of 36 children and five caregivers were diagnosed with COVID-19 during the study period. Of the 206 preschoolers who had close contact with the infected persons, only 16 became positive (7.6%). Secondary transmission from the 36 preschool children to the parents as HCWs occurred in 19 (61%) out of 31 parents. Three hospitalized patients were judged to have unsafe contact with the infected HCWs but this did not result in their infections, making a total of zero transmission from the nursery school to the hospital.

CONCLUSIONS

Children at the nursery school are potential reservoirs for nosocomial transmissions at the affiliated hospital, but multiple practical measures might have prevented them to occur.

An Outline of the Immunogenic Potential of Progressing SARSCoV- 2 Vaccine Technologies among Children and Adolescents

BACKGROUND

SARS-CoV-2, a highly dynamic beta-coronavirus, can afflict all age groups. Notably, over 16100 mortalities have been recorded among children as yet. In this regard, many vaccine projects are operational to assess immuno-potency among young cohorts. A bulk of reports have evidenced the efficacy of these immunization technologies in the elderly population, though the impact is yet to be determined among children.

OBJECTIVES

This review is envisioned to outline the current efficacy of contributing vaccine technologies and examine the dose-dependent impact of immunization regimens in lowering the risks of SARS-CoV-2 infections among children and adolescents. Furthermore, the current review exclusively estimated the vaccine impact at current doses.

METHODS

A total of 52 research papers extracted from PubMed, Pubmed Central, Science Direct, Research Gate, Google Scholar and Semantic Scholar were screened along with an emphasis on patents. Inclusion criteria involved all published reports directly or indirectly linked to the contributing vaccine candidates that are operational among the young cohort. Unrelated research papers were excluded from the study. Key search terminologies included information on vaccine identifiers, such as name, type and clinical trial ID, and successively restricted to children and adolscents age groups.

RESULTS

Several vaccine designs, such as mRNA-based vaccinations, viral vector vaccines, DNA vaccines, inactivated vaccines, recombinant vaccines, and protein-based immunizations, are being examined at various stages of clinical trials to gauge the effects on children and adolescents. With reference to the published reports, the mRNA 1273 (1610 GMT; 6-10 yrs, 1401 GMT; 12-15 yrs), BNT162b2 (1407 GMT; 6 months- <2 yrs, 1535 GMT; 2-4 yrs, 4583 GMT; 5-11 yrs, 1239.5 GMT; 12-15 yrs) and Ad5 nCoV (1037.5 GMT; 6-17 yrs) offered relatively high neutralization titers with sharp seroconversion rates compared to MVC-COV1901 (648.5 GMT; 12-17 yrs) and ZyCoV-D (133.49 GMT; 12-17 yrs), which produced modest immune responses.

CONCLUSION

Currently, the WHO is analyzing emerging evidence to issue an emergency use list of vaccines for vaccinating children and adolescents.

"Direct and indirect impacts of the COVID-19 pandemic on operational conduct of pediatric vaccine clinical trials"

The coronavirus 2019 (COVID-19) pandemic, as well as the resulting public health measures, impacted many aspects of society. The conduct of important pediatric vaccine trials was among these. Analyzing data from six ongoing non-COVID-19 pediatric vaccine trials we aimed to assess the operational impact of the COVID-19 pandemic using descriptive analyses. We identified multiple operational disruptions in trial conduct. Additionally, we identified higher percentages of missed routine vaccinations than investigational vaccines throughout the observation period. Overall, the impact of the COVID-19 pandemic was most apparent early in the pandemic period while adaptations to the pandemic were developed; however, some disruptions persisted throughout the observation period. Pediatric vaccine clinical trials are critical to developing new and/or improved vaccines for the pediatric population. Continued evaluation of the impacts of COVID-19 on pediatric vaccine clinical trials is warranted.

Monte Carlo Regression for Evaluating Children's Role in the Pandemic Spread on the Example of Delta COVID-19 Wave

BACKGROUND

The children's role in transmitting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the familial settings is uncertain. We aimed to assess how often children were the index cases transmitting SARS-CoV-2 into their households during the Delta wave, and to identify risk factors of children being the index case.

METHODS

In this prospective survey study, we collected information regarding household members of SARS-CoV-2-positive children tested in a single tertiary hospital. Some patients were tested with polymerase chain reaction and those samples were typed and classified as Delta or non-Delta variant. We have used the Monte Carlo approach to assess predictors of children being the index case in the household.

RESULTS

We surveyed 629 families and 515 of them fulfilled inclusion criteria. The child was the index case in 359 (69.71%) households. Attending childcare facilities in all age groups was positively associated with being the index case in the household [nursery, estimate = 1.456, 95% confidence interval (CI): 1.456-1.457, P < 0.001; kindergarten, estimate = 0.899, 95% CI: 0.898-0.900, P = 0.003; school, estimate = 1.23, 95% CI: 1.229-1.231, P = 0.001]. The same association was present in the subgroup of the families with the predominant Delta variant, but not in the subgroup with the predominant non-Delta variant.

CONCLUSIONS

Attending childcare and educational facilities might be a significant predictor of a child being the SARS-CoV-2 index case in their household. Children's role in driving the SARS-CoV-2 pandemic changes in consecutive waves. The Monte Carlo approach can be applied to assess risk factors of infectious agents' spread in future epidemics.

Clinical Syndromes Related to SARS-CoV-2 Infection and Vaccination in Pediatric Age: A Narrative Review

This narrative review aims to report the main clinical manifestations, therapeutic strategies, outcomes, and complications of acute SARS-CoV-2 infection in childhood and to summarize the data relating the SARS-CoV-2 vaccination efficacy and safety in pediatric age. SARS-CoV-2 infection mostly occurs asymptomatically in the pediatric population, while multisystem inflammatory syndrome in children (MIS-C) represents the most severe coronavirus disease 2019 (COVID-19)-related illness, a life-threatening event with a high morbidity rate. After the development of SARS-CoV-2 vaccines and their subsequent approval in children, the rate of infection as well as the number of its related complications have shown a drastic decrease. Fully vaccinated children are protected from the risk of developing a severe disease and a similar protective role has been observed in the reduction of complications, in particular MIS-C. However, long-lasting immunity has not been demonstrated, booster doses have been required, and reinfection has been observed. With regards to vaccine safety, adverse events were generally mild to moderate in all age groups: local adverse events were the most commonly reported. Nevertheless, a potential association between SARS-CoV-2 vaccine and the subsequent development of inflammatory manifestations has been suggested. Myocarditis has rarely been observed following vaccination; it appeared to be more frequent among adolescent males with a mild clinical course leading to a complete recovery. SARS-CoV-2 vaccine-related MIS-C cases have been described, although a univocal definition and an exact time interval with respect to vaccination has not been reported, thus not establishing a direct causal link. Current evidence about COVID-19 vaccination in children and adolescents suggest that benefits outweigh potential risks. Long-term data collection of the post-authorization safety surveillance programs will better define the real incidence of SARS-CoV-2 vaccine-related complications in the pediatric population.

SARS-CoV-2 excretion kinetics in nasopharyngeal and stool samples from the pediatric population

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for serious respiratory infections in humans. Even in the absence of respiratory symptoms, gastrointestinal (GI) signs were commonly reported in adults and children. Thus, oral-fecal transmission was suspected as a possible route of infection. The objective of this study was to describe RNA shedding in nasopharyngeal and stool samples obtained from asymptomatic and symptomatic children and to investigate virus viability.

Methods

This study included 179 stool and 191 nasopharyngeal samples obtained from 71 children, which included symptomatic (n = 64) and asymptomatic (n = 7) ones. They were collected every 7 days from the onset of the infection until negativation. Viral RNA was detected by real-time RT-PCR, targeting the N and ORF1 genes. Whole-genome sequencing was performed for positive cases. Viral isolation was assessed on Vero cells, followed by molecular detection confirmation.

Results

All cases included in this study (n = 71) were positive in their nasopharyngeal samples. SARS-CoV-2 RNA was detected in 36 stool samples obtained from 15 out of 71 (21.1%) children; 13 were symptomatic and two were asymptomatic. Excretion periods varied from 7 to 21 days and 7 to 14 days in nasopharyngeal and fecal samples, respectively. Four variants were detected: Alpha (n = 3), B.1.160 (n = 3), Delta (n = 7), and Omicron (n = 1). Inoculation of stool samples on cell culture showed no specific cytopathic effect. All cell culture supernatants were negative for RT-qPCR.

Conclusion

Our study demonstrated nasopharyngeal and fecal shedding of SARS-CoV-2 RNA by children up to 21 and 14 days, respectively. Fecal shedding was recorded in symptomatic and asymptomatic children. Nevertheless, SARS-CoV-2 was not isolated from positive stool samples.

[The burden of COVID-19 in a heterogeneous population of immunocompromised patients - realities of the postpandemic]

On July 3, 2023, an interdisciplinary Council of Experts "The burden of COVID-19 in a heterogeneous population of immunocompromised patients - post-pandemic realities" was held in Moscow with leading experts in pulmonology, rheumatology, hematology, oncology, nephrology, allergology-immunology, transplantation, and infectious diseases. The aim of the meeting was to discuss the current clinical and epidemiologic situation related to COVID-19, the relevance of disease prevention strategies for high-risk patients. The experts addressed the following issues: 1) the disease burden of COVID-19 in 2023 for patients with immunodeficiency in different therapeutic areas; 2) the place of passive immunization with monoclonal antibodies as a method of COVID-19 prophylaxis among immunocompromised patients; 3) prerequisites for the inclusion of passive immunization of immunocompromised patients into routine clinical practice.

A Lung ultrasound-based comparison of postoperative respiratory outcome after pediatric congenital heart surgery in COVID-19 recovered and COVID-19 unaffected children-a pilot study

Background

COVID-19 is known to affect the alveolar-capillary membrane and interstitial tissue. Cardiopulmonary bypass (CPB) is proven to cause "pump-lung" syndrome. Little is known about the subgroup of COVID-19-recovered children undergoing cardiac surgeries under CPB.

Aim

To compare the lung ultrasound score (LUSS) and morbidity of COVID-19-recovered children to those without COVID-19 after congenital cardiac surgery.

Setting and Design

Prospective observational pilot study at a tertiary care institution.

Materials and Methods

The study was carried out on 15 COVID-recovered children and 15 matched controls (Group B) posted for congenital cardiac surgery. COVID-recovered children were further divided into those who received in-hospital care for COVID (Group C) and those who did not (Group A). LUSS measured immediately after cardiac surgery was compared between the groups. PaO2/FiO2 ratio, incidence of pulmonary infection, re-intubation rate, duration of ventilation, in-hospital mortality, and 30-day mortality were also compared between the groups.

Results

LUSS was comparable between Groups A and B (mean difference = 1.467, P = 0.721). Compared to the control group, Group C showed higher LUSS (mean difference = 11.67, P < 0.001), lower PaO2/FiO2 ratio (207.8 ± 95.49 Vs 357.6 ± 63.82, P = 0.003), and one in-hospital mortality. A significant negative correlation was seen between LUSS and PaO2/FiO2 ratio (rs = -0.75, P < 0.001).

Conclusion

LUSS was not higher in COVID-recovered children. Children with a history of severe COVID-19 recorded higher LUSS, in-hospital mortality, duration of ICU stay, and duration of ventilation.

Classification of SARS-CoV-2 Pediatric Hospitalizations: Delta vs Omicron Variant

OBJECTIVES

To classify COVID-19 pediatric hospitalizations based on reason for admission ("for COVID" or "with COVID") and to compare disease severity and age between the delta and omicron variant predominant time frames.

METHODS

This was a retrospective study in patients aged ≤18 years who were hospitalized at a large, tertiary care pediatric hospital for COVID-19 from July 2021 to February 2022. Disease severity was determined based on length of stay, PICU admission, and Remdesivir receipt. A χ2 analysis and a Cochran-Mantel-Haenszel test were used to analyze relationships between presumed variant type with admission reason, disease severity, and age.

RESULTS

There were 492 patients included with more admissions during the omicron variant predominant time frame (n = 307). More patients were admitted "for COVID" during the delta variant predominant time frame compared with the omicron variant predominant time frame (P < .001) with interrater reliability testing indicating substantial agreement between reviewers. PICU admissions (P < .001), receipt of remdesivir (P < .001), and length of stay (P < .001) were greater during the delta variant predominant time frame. Hospitalizations "for COVID" were more common in patients aged <5 years during both the delta (odds ratio, 2.6; 95% confidence interval, 1.2-5.7) and omicron (odds ratio, 5.7; 95% confidence interval, 3.4-9.4) predominant time frames compared with older patients.

CONCLUSIONS

There was a higher proportion of symptomatic COVID-19 hospitalizations with higher disease severity during the delta variant predominance, indicating greater disease severity during earlier periods of the pandemic despite lower hospitalization rates.

Kidney involvement in children during the SARS-CoV-2 Omicron variant pandemic

BACKGROUND

As the coronavirus disease-2019 (COVID-19) pandemic continues, driven by the Omicron variant, infection rates in children have recently rapidly surged compared with previous years. We aimed to investigate the presentation of kidney involvement in children after Omicron variant severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection.

METHODS

We retrospectively reviewed the medical records of pediatric patients who presented with kidney disease with a temporal relationship with COVID-19 between January and August 2022 in a single tertiary center in Korea.

RESULTS

Fifteen children presented with kidney involvement after Omicron variant infection, with a median age of 10.6 (6.8-18.3) years. None of the patients exhibited severe respiratory symptoms apart from cough and sore throat. The median time from infection to renal symptom onset was 3 (0-49) days. Among 10 patients with underlying kidney disease, six had previously been diagnosed with nephrotic syndrome (NS) that relapsed after COVID-19 infection, two with immunoglobulin A nephropathy (IgAN) experienced transient gross hematuria (GHU) with or without acute kidney injury (AKI), and two with kidney transplantation presented with AKI. Of the five patients without underlying kidney disease, one patient had NS, and the other four patients had GHU and proteinuria (PU), of whom one was eventually diagnosed with Henoch Shönlein Purpura nephritis (HSPN), and one with rhabdomyolysis. The seven patients with NS (1 new-onset, 6 relapsed) had uneventful remission with corticosteroid therapy. Apart from one patient with new-onset HSPN, GHU and PU resolved spontaneously in all affected patients, and AKI also resolved with supportive care.

CONCLUSIONS

Kidney involvement subsequent to Omicron variant COVID-19 exhibited various, but mostly mild manifestations in children.

Acute COVID-19 in unvaccinated children without a history of previous infection during the delta and omicron periods

BACKGROUND

The Omicron variant has been the predominant severe acute respiratory syndrome coronavirus 2 variant circulating in Korea since January 2022. This study evaluated and compared the clinical characteristics of children with coronavirus disease 2019 (COVID-19) between the Delta and Omicron periods.

METHODS

The medical records of children aged < 12 years diagnosed with acute COVID-19 (<2 weeks of symptom onset) at seven university-affiliated hospitals were retrospectively reviewed. Children with a previous history of COVID-19 or vaccination were excluded. The clinical characteristics of the included children during the Delta (1 August 2021 to 15 January 2022) and Omicron (16 January to 30 June 2022) periods were compared.

RESULTS

Among the 515 children included in the study, 36 (7.0%) and 479 (93.0%) were diagnosed with COVID-19 during the Delta and Omicron periods, respectively. A total of 142 (27.6%) were hospitalized, and the hospitalization rate was higher during the Delta period than the Omicron period (91.7% vs. 22.8%, p < 0.001). The incidence of fever (p = 0.009), vomiting (p = 0.031), and seizures (p = 0.007) was higher during the Omicron period, whereas the incidence of rhinorrhea (p = 0.027) was higher during the Delta period. Clinical severity and outcomes were comparable between the two periods. During the Omicron period, 6.4% of the hospitalized children received oxygen therapy and 1.8% received intensive care.

CONCLUSION

The incidence of fever and seizures was higher during the Omicron period in pediatric patients without a history of vaccination or previous COVID-19. However, the clinical severity was similar during both periods.

Pediatric infection with the Omicron variant increases the risks of febrile seizures among COVID-19 infected children

Background

The Omicron variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is less likely to cause severe disease in children than the other variants but has become an increasing cause of febrile seizures (FS) among children. In this case-control study, we aimed to examine the risk factors associated with FS in children infected with the COVID-19 Omicron variant and related treatment modalities.

Methods

This retrospective case-control study includes 113 subjects infected with the COVID-19 Omicron variant, grouped into 45 cases (those with FS) and 68 controls (those without FS). Data on clinical features, laboratory parameters, and treatment modalities were collected and analyzed.

Results

Approximately 5.74% of COVID-19 infected children developed COVID-19-associated FS. Children with COVID-19 and high body temperatures [RR 1.474; (95% CI: 1.196-1.818), p < 0.001], previous history of FS [RR 1.421; (95% CI: 1.088-1.855), p = 0.010], high procalcitonin levels [RR 1.140; (95% CI: 1.043-1.246), p = 0.048] and high neutrophil counts [RR 1.015; (95% CI: 1.000-1.029), p = 0.048] were more likely to experience FS than the controls. In contrast, children with COVID-19 and low eosinophil counts, low hemoglobin levels, and cough had a lower risk of developing FS [RR 0.494; (95% CI: 0.311-0.783), p = 0.003], [RR 0.979; (95% CI: 0.959-0.999), p = 0.044]; and [RR 0.473 (95% CI 0.252-0.890), p = 0.020]; respectively. Children with FS received more anti-flu medications than those without.

Conclusion

A significant increase in FS was observed in children with Omicron SARS-CoV-2 infection. A higher body temperature, a history of FS, a higher procalcitonin level, and a high neutrophil count were all associated with an increased risk of FS in children with COVID-19. The risk of developing FS was lower in children with COVID-19 and low eosinophil counts and hemoglobin levels than in those without.

Clinical features of COVID-19 in Italian outpatient children and adolescents during Parental, Delta, and Omicron waves: a prospective, observational, cohort study

Introduction

COVID-19 features changed with the Omicron variant of SARS-CoV-2 in adults. This study aims to describe COVID-19 symptoms in children and adolescents during the Parental, Delta, and Omicron eras.

Methods

A single-centre, prospective observational study was conducted on individuals aged 0-20 years attending the University Hospital of Padua (Italy) from April 2020 to December 2022. COVID-19 cases were defined by positive SARS-CoV-2 molecular detection and/or serology; patient/family symptoms and virological positivity were considered to determine the infection onset. Variables were summarized and compared using appropriate tests of descriptive statistics.

Results

A total of 509 cases [46% female, median age eight years (IQR: 4-12)] were studied. Three-hundred-eighty-seven (76%), 52 (10%), and 70 (14%) subjects experienced COVID-19 during the Parental, Delta, and Omicron waves, respectively. All subjects developed an asymptomatic/mild COVID-19. Overall, the most frequent symptoms were fever (47%) and rhinitis (21%), which showed a significant increasing incidence from the Parental to Omicron waves (p < 0.001). Conversely, diarrhea was most common during the pre-Omicron eras (p = 0.03). Stratifying symptoms according to the age group, fever, rhinitis, and skin rashes were observed more frequently among infants/toddlers; conversely, fatigue was more common in children older than five years. The duration of symptoms was similar across different SARS-CoV-2 variants of concern (VOCs); conversely, the number of symptoms varied according to the age group (p < 0.0001).

Discussion

This study showed differences in COVID-19 clinical presentation among infants, children, and adolescents and confirmed Omicron infection is more likely to be associated with upper respiratory symptoms. However, further population-based studies are needed to support these findings. In addition, active surveillance will play a crucial role in assessing the disease severity of future VOCs.

Factors associated with parental intention to vaccinate their preschool children against COVID-19: a cross-sectional survey in urban area of Jakarta, Indonesia

Purpose

We reported a survey-based study assessing the parental intention to vaccinate children of 5 to 7 years old against coronavirus disease 2019 (COVID-19). The aim of this study is to assess factors influencing the parental intention to vaccinate their children against COVID-19.

Materials and Methods

This study adopted a cross-sectional design, held at the public health center of Senen district, Jakarta, Indonesia from November 1-30, 2022. The off-line questionnaires were distributed via the school administrator to all eligible parents. Factors associated with intention to vaccinate were analyzed with the regression logistic models.

Results

Of the 435 parents in this study, 215 had already vaccinated their children against COVID-19 (49.4%), and the overall intention of the participants to vaccinate was 69.7%. Factors associated with intention to vaccinate the children against COVID-19 were parental employment status, parental COVID-19 vaccine status and concern of contracting COVID-19. Parents who are employed, had completed vaccines with COVID-19 booster vaccine, and had concern of their children contracting COVID-19 were more likely to vaccinate their children (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.22-3.69; p=0.011; OR, 2.15; 95% CI, 1.21-3.83; p=0.013; OR, 2.40; 95% CI, 1.34-4.30; p=0.004, respectively). Concern on the vaccine's side effects was negatively associated with the willingness to vaccinate.

Conclusion

This study showed that childhood COVID-19 vaccine only covered half of the population, with parental intentions for childhood COVID-19 vaccination being high, reaching almost two-thirds of the study participants. Factors influencing parental intentions were employment status, parental COVID-19 vaccine status, concerns about COVID-19 and concerns about vaccine side effects.

Humoral immune responses to inactivated COVID-19 vaccine up to 1 year in children with chronic hepatitis B infection

Background

Inactivated SARS-CoV-2 vaccination has recently been approved for children aged 3-17 years in China. However, data on long-term humoral responses to inactivated vaccines in children with chronic hepatitis B (CHB) are still limited.

Methods

In this prospective observational study, CHB children after primary inactivated SARS-CoV-2 vaccines were recruited consecutively and followed up for 1 year. CHB adults from another cohort study (NCT05007665) were used as a control. The receptor-binding domain IgG antibody (anti-RBD-IgG), neutralizing antibody (NAb), neutralization against Omicron (BA2.12.1, BA.4 and BA.5), and memory B -cell (MBC) responses were evaluated.

Results

Overall, 115 CHB children and 351 CHB adults were included in this analysis. The antibody titers decreased over the first ~180 days and then plateaued up to 1 year in CHB children. However, lower and faster declines in antibody responses were observed in CHB adults. Interestingly, the seroprevalence of antibodies was still high after over 8 months in CHB children (anti-RBD-IgG [90%] and NAbs [83%]). However, neutralization against Omicron subvariants was significantly reduced in CHB children (-3.68-fold to -8.60-fold). Notably, neutralization against the BA.5 subvariant was obviously diminished in CHB children compared with adults. Moreover, CHB children had similar RBD-specific MBCs but higher RBD-specific atypical MBCs compared with adults.

Conclusion

Inactivated vaccination could elicit more robust and durable antibody responses to the wild-type SARS-CoV-2 strain in CHB children than in CHB adults but showed inferior responses to Omicron subvariants (especially to the BA.5 strain). Hence, new Omicron-related or all-in-one vaccines are needed immediately for CHB children.

Epidemiology of COVID-19 among Children and Adolescents in Sudan 2020-2021

Children and adolescents account for a small proportion of confirmed COVID-19 cases, with mild and self-limiting clinical manifestations. The distribution and determinants of COVID-19 among this group in Sudan are unclear. This study used national COVID-19 surveillance data to study the epidemiology of COVID-19 among children and adolescents in Sudan during 2020-2021. A cross-sectional study was performed to estimate the reported incidence of children and adolescents with COVID-19; the clinical features; and the mortality among those who tested positive for COVID-19. A total of 3150 suspected cases of COVID-19 infection fulfilled the study criteria. The majority of cases were above 10 years of age, 52% (1635) were males, and 56% (1765) were asymptomatic. The reported incidence rates of COVID-19 among children and adolescents in Sudan was 1.3 per 10,000 in 2021. Fever, cough, and headache were the most frequent symptoms reported among the suspected cases. The case fatality rate was 0.2%. Binary logistic regression revealed that loss of smell was the most significantly associated symptom with a positive test. We recommend further study to identify risk factors. Additionally, we recommend including these age groups in the vaccination strategy in Sudan.

Prevalence and associating factors of long COVID in pediatric patients during the Delta and the Omicron variants

Introduction

The number of pediatric COVID-19 infections is increasing; however, the data on long COVID conditions in children is still limited. Our study aimed to find the prevalence of long COVID in children during the Delta and Omicron waves, as well as associated factors.

Methods

A single-center prospective cohort study was conducted. We included 802 RT-PCR-confirmed COVID-19 pediatric patients in the Delta and Omicron periods. Long COVID was defined as having symptoms for ≥3 months after infection. Parents and/or patients were interviewed by phone. Multivariable logistic regression was performed to find associated factors with long COVID.

Results

The overall prevalence of long COVID was 30.2%. The Delta period had more prevalence than the Omicron (36.3% vs. 23.9%). Common symptoms for patients 0-3 years' old were loss of appetite, rhinorrhea, and nasal congestion. Conversely, patients 3-18 years' old had hair loss, dyspnea on exertion, rhinorrhea, and nasal congestion. However, there was no significant negative impact on daily life. Most symptoms improved after a 6-month follow-up. Factors associated with long COVID-19 conditions were infection during the Omicron period (adjusted OR: 0.54; 95% CI: 0.39-0.74, P < 0.001), fever (adjusted OR: 1.49, 95% CI: 1.01-2.20, P = 0.04) and rhinorrhea (adjusted OR: 1.47, 95% CI: 1.06-2.02, P = 0.02).

Conclusion

Infection during the Omicron wave has a lower prevalence of long COVID. The prognosis is often favorable, and most symptoms gradually become less. However, pediatricians may schedule appointments to surveil long COVID in children with fever or rhinorrhea as an initial symptom.

Clinical Features of COVID-19 in Pediatric Rheumatic Diseases: 2020-2022 Survey of the Pediatric Rheumatology Association of Japan

Coronavirus disease 2019 (COVID-19) in children can be compounded by concurrent diseases and immunosuppressants. For the first time, we aimed to report the clinical features of concurrent COVID-19 and pediatric rheumatic disease (PRD) in Japan. Pediatric Rheumatology Association of Japan members were surveyed between 1 April 2020 and 31 August 2022. Outcome measurements included the clinical features of concurrent PRD and COVID-19. Questionnaire responses were obtained from 38 hospitals. Thirty-one hospitals (82%) had children with PRD and COVID-19. The female-to-male ratio in these children (n = 156) was 7:3, with half aged 11-15 years. The highest proportion of children with PRD and COVID-19 was accounted for by juvenile idiopathic arthritis (52%), followed by systemic lupus erythematosus (24%), juvenile dermatomyositis (5%), scleroderma (4%), and Takayasu arteritis (3%). Of children with PRD, a significant majority (97%) were found to be asymptomatic (10%) or presented with mild symptoms (87%) of the COVID-19 infection. No severe cases or deaths were observed. Regarding the use of glucocorticoids, immunosuppressants, or biologics for PRD treatment before COVID-19, no significant difference was found between asymptomatic/mild and moderate COVID-19 in children with PRD. Therefore, COVID-19 is not a threat to children with PRD in Japan.

Comparison of the reactogenicity and immunogenicity between two-dose mRNA COVID-19 vaccine and inactivated COVID-19 vaccine followed by an mRNA vaccine in children aged 5-11 years

To compare the reactogenicity and immunogenicity between the two-dose mRNA COVID-19 vaccine regimen and one or two doses of inactivated vaccine followed by an mRNA vaccine regimen in healthy children between 5 and 11 years of age, a prospective cohort study was performed at King Chulalongkorn Memorial Hospital in Thailand between March to June 2022. Healthy children between 5 and 11 years of age were enrolled and received the two-dose mRNA COVID-19 vaccine (BNT162b2) regimen or the inactivated (CoronaVac) vaccine followed by the BNT162b2 vaccine regimen. In addition, healthy children who received two doses of BBIBP-CorV between 1 and 3 months prior were enrolled to receive a heterologous BNT162b2 as a third dose (booster). Reactogenicity was assessed by a self-reported online questionnaire. Immunogenicity analysis was performed to determine binding antibodies to wild-type SARS-CoV-2. Neutralizing antibodies to Omicron variants (BA.2 and BA.5) were tested using the focus reduction neutralization test. Overall, 166 eligible children were enrolled. Local and systemic adverse events which occurred within 7 days after vaccination were mild to moderate and well-tolerated. The two-dose BNT162b2, CoronaVac followed by BNT162b2, and two-dose BBIBP-CorV followed by BNT162b2 groups elicited similar levels of anti-receptor-binding domain (RBD) IgG. However, the two-dose BNT162b2 and two-dose BBIBP-CorV followed by BNT162b2 groups elicited higher neutralizing activities against the Omicron BA.2 and BA.5 variant than the CoronaVac followed by BNT162b2 group. The CoronaVac followed by BNT162b2 group elicited low neutralizing activities against the Omicron BA.2 and BA.5 variant. A third dose (booster) mRNA vaccine should be prioritized for this group.

Intranasal infection by SARS-CoV-2 Omicron variants can induce inflammatory brain damage in newly-weaned hamsters

SummaryIntranasal infection of newly-weaned Syrian hamsters by SARS-CoV-2 Omicron variants can lead to brain inflammation and neuron degeneration with detectable low viral load and sparse expression of viral nucleoprotein.AbstractChildren infected by SARS-CoV-2 Omicron variant may develop neurological complications. To study the pathogenesis in the growing brain, we intranasally challenged newly-weaned or mature hamsters with SARS-CoV-2 Omicron BA.2, BA.5 or Delta variant. Omicron BA.2 and Delta infection produced a significantly lower viral load in the lung tissues of newly-weaned than mature hamsters despite comparable histopathological damages. Newly-weaned hamsters had higher brain viral load, significantly increased cerebrospinal fluid concentration of TNF-α and CXCL10 and inflammatory damages including mild meningitis and parenchymal vascular congestion, despite sparse expression of nucleocapsid antigen in brain cells. Furthermore, 63.6% (28/44) of all SARS-CoV-2 infected newly-weaned hamsters showed microgliosis in olfactory bulb, cerebral cortex and hippocampus. In infected mature hamsters, microgliosis were observed mainly in olfactory bulb and olfactory cortex of 35.3% (12/34) of their brains. Neuronal degeneration was found in 75% (33/44) of newly-weaned hamsters affecting multiple regions including olfactory bulb, olfactory cortex, midbrain cortex and hippocampus, while such changes were mainly observed in hippocampus of mature hamsters. Importantly, similar brain histopathology was observed in Omicron BA.5 infected newly-weaned hamsters. Our study suggested that SARS-CoV-2 may affect the brain at young age. This kind of brain involvement and histological changes are not virus variant or subvariant specific. Incidentally, moderate amount of eosinophilic infiltration was observed in the mucosa of nasal turbinate and trachea of newly-weaned hamsters infected by Omicron BA.2 and BA.5 but not Delta variant. This histological finding is consistent with the higher incidence of laryngotracheobronchitis in young children infected by the Omicron variant.

Multiple influences of the COVID-19 pandemic on children with diabetes: Changes in epidemiology, metabolic control and medical care

The coronavirus disease 2019 (COVID-19) pandemic has heavily affected health worldwide, with the various forms of diabetes in children experiencing changes at various levels, including epidemiology, diabetic ketoacidosis rates and medical care. Type 1 diabetes showed an apparent increase in incidence, possibly owing to a direct damage of the virus to the β-cell. Diabetic ketoacidosis also increased in association with the general fear of referring patients to the hospital. Most children with diabetes (both type 1 and type 2) did not show a worsening in metabolic control during the first lockdown, possibly owing to a more controlled diet by their parents. Glucose sensor and hybrid closed loop pump technology proved to be effective in all patients with type 1 diabetes during the pandemic, especially because the downloading of data allowed for the practice of tele-medicine. Telemedicine has in fact grown around the world and National Health Systems have started to consider it as a routine activity in clinical practice. The present review encompasses all the aspects related to the effects of the pandemic on the different forms of diabetes in children.

Importance of ACE2 for SARS-CoV-2 Infection of Kidney Cells

In late 2019, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of coronavirus disease 2019 (COVID-19) emerged in China and spread rapidly around the world, causing an ongoing pandemic of global concern. COVID-19 proceeds with moderate symptoms in most patients, whereas others experience serious respiratory illness that requires intensive care treatment and may end in death. The severity of COVID-19 is linked to several risk factors including male sex, comorbidities, and advanced age. Apart from respiratory complications, further impairments by COVID-19 affecting other tissues of the human body are observed. In this respect, the human kidney is one of the most frequently affected extrapulmonary organs and acute kidney injury (AKI) is known as a direct or indirect complication of SARS-CoV-2 infection. The aim of this work was to investigate the importance of the protein angiotensin-converting enzyme 2 (ACE2) for a possible cell entry of SARS-CoV-2 into human kidney cells. First, the expression of the cellular receptor ACE2 was demonstrated to be decisive for viral SARS-CoV-2 cell entry in human AB8 podocytes, whereas the presence of the transmembrane protease serine 2 (TMPRSS2) was dispensable. Moreover, the ACE2 protein amount was well detectable by mass spectrometry analysis in human kidneys, while TMPRSS2 could be detected only in a few samples. Additionally, a negative correlation of the ACE2 protein abundance to male sex and elderly aged females in human kidney tissues was demonstrated in this work. Last, the possibility of a direct infection of kidney tubular renal structures by SARS-CoV-2 was demonstrated.

Children’s Symptoms with a Febrile Illness and a Positive or Negative Test of SARS-CoV-2 during the Omicron Wave

Febrile infections are common in childhood. Children can be infected with SARS-CoV-2, but their course is milder than in adults. So far, a comparison between febrile infections with a positive or negative Corona test with the Omicron variant is missing. The data used are from the FeverApp registry, which collects parent-reported data on febrile infections in children and informs about fever management. A comparison of symptomatic differences between episodes with a positive or negative Corona test was performed using Χ2-tests. During the Omicron wave, reported tests doubled and positive test results nearly 12-folded. In episodes with positive Corona saliva tests, more cough, fatigue, disturbed smell/taste, limb pain, sore throat, signs of serious sickness, and touch sensitivity were reported. Children with a negative Corona test show more tonsillitis, teething, any pain symptoms, earaches, and rashes. Thus, there are some significant differences between febrile infections with a positive or negative Corona test, but symptoms are present on both sides. The omicron variant seems to be more infectious than the alpha or delta variants in children, but the symptoms remain mild and do not differ much from other febrile infections.

Children's SARS-CoV-2 Infection and Their Vaccination

SARS-CoV-2, a novel coronavirus, causes respiratory tract infections and other complications in affected individuals, and has resulted in numerous deaths worldwide. The unprecedented pace of its transmission worldwide, and the resultant heavy burden on healthcare systems everywhere, prompted efforts to have effective therapeutic strategies and vaccination candidates available to the global population. While aged and immunocompromised individuals form a high-risk group for COVID-19 and have severe disease outcome, the rate of infections among children has also increased with the emergence of the Omicron variant. In addition, recent reports of threatening SARS-CoV-2-associated complications in children have brought to the forefront an urgent necessity for vaccination. In this article, we discuss the current scenario of SARS-CoV-2 infections in children with a special focus on the differences in their immune system response as compared to adults. Further, we describe the various available COVID-19 vaccines, including the recent bivalent vaccines for children, in detail, intending to increase willingness for their acceptance.

Development of patient- and observer-reported outcome measures to assess COVID-19 signs and symptoms in children and adolescents

BACKGROUND

The Symptoms of Infection with Coronavirus-19 (SIC) is a 30-item patient-reported outcome measure to evaluate the presence and severity of COVID-19 signs/symptoms in adults. This study expanded the context of use of the adult SIC among adolescents aged 12-17 years and supported a pediatric adaptation (the Pediatric SIC [PedSIC]) for caregiver assessment of signs/symptoms in children aged < 12 years.

METHODS

Draft versions of the PedSIC and reference materials containing sign/symptom definitions for adolescents, based on an assessment of the reading level of SIC items by a professional linguist, were developed to facilitate accurate completion of the SIC by adolescents and observer-report (PedSIC) by caregivers. For adolescents, reference materials were intended to provide definitions for selected signs/symptoms identified to have a higher reading level. Iterative rounds of cognitive debriefing interviews were conducted from November 2020 to January 2021 to evaluate adolescent understanding of the SIC reference materials and inform refinement of the PedSIC for caregivers of children too young to reliably self-report. Participants were identified via databases of individuals who previously expressed interest in participating in qualitative research and were then screened for eligibility. Recruitment quotas were established to improve sample diversity. Thematic analysis and descriptive statistics were used to assess qualitative and demographic data, respectively.

RESULTS

Nine healthy adolescents (mean [SD, range] age, 14 [1.76, 12-17] years, 56% female, 22% non-White; round 1, n = 6; round 2, n = 3) and 17 caregivers (mean [SD, range] age, 34 [6.28, 26-41] years, 59% female, 35% non-White; round 1, n = 9; round 2, n = 8) were interviewed. Adolescents understood the majority of signs/symptoms (22 of the 30 SIC items) without assistance or use of the reference materials during the cognitive debriefing interview. Definitions were added to the reference materials for 5 additional items, and clarifications provided to existing definitions for 3 items. Seven observer-report (PedSIC) items were modified following feedback from caregivers of healthy young children. Reference materials (similar to those for adolescent use) were developed to support caregiver understanding of the intent of the PedSIC items collecting input from children ages ≥ 5- < 12 years.

CONCLUSIONS

Results support using the SIC, PedSIC, and their associated reference materials to evaluate the presence and severity of COVID-19 signs/symptoms in adolescents and children aged < 12 years via caregiver-supported report, respectively.

Omicron in Infants-Respiratory or Digestive Disease?

The Omicron variant of SARS-CoV-2 has caused a large number of cases and hospitalizations in the pediatric population. Infants due to their age are susceptible to viral infections that may have a worse prognosis. Therefore, the aim of the current study has been to characterize the clinical features and the outcome of infants hospitalized with confirmed SARS-CoV-2 infection during the Omicron wave. We conducted a retrospective study of all consecutive infants hospitalized with symptomatic COVID-19 and no other co-infections, from January to September 2022 in one of the largest infectious diseases hospitals from Bucharest, Romania. A total of 613 infants were included in the analysis. The median age was 5 months (IQR: 3, 8 months). The clinical features were dominated by fever (96.4%), cough (64.8%) and loss of appetite (63.3%), and overall, respiratory symptoms were the most numerous (76.0%). Infants between 1-3 months old had a 1.5-fold increased risk of elevated alanine aminotransferase (ALT) values, and a longer length of hospitalization as compared to older infants. Infants between 7-9 months of age had 1.5-fold higher odds of loss of appetite, 1.7-fold more frequent cough and 1.6-fold more frequent digestive symptoms compared to infants in other age groups. The presence of digestive symptoms increased the probability of hepatic cytolysis (increased ALT) by 1.9-fold. Continued monitoring of COVID-19 among infants is very necessary, given the progressive character of SARS-CoV-2, in order to take correct and rapid therapeutic measures and to adapt to clinical changes driven by viral variant change.

Variability in the Clinical Course of COVID-19 in a Retrospective Analysis of a Large Real-World Database

The COVID-19 pandemic proceeds in waves, with variable characteristics of the clinical picture resulting from the evolution of the SARS-CoV-2 virus. This study aimed to compare the epidemiological characteristics, symptomatology, and outcomes of the disease in patients hospitalized for COVID-19 during periods of different variants dominance. Comparing the periods of dominance of variants preceding the Delta variant, the Delta period was characterized by a higher share of hospitalized females, less frequent comorbidities among patients, and a different age distribution. The lowest need for oxygen therapy and mechanical ventilation was observed under Omicron dominance. The triad of classic COVID-19 symptoms, cough, fever, dyspnoea, and fatigue, were most prevalent during the Delta period, and significantly less common under the Omicron dominance. During the Omicron period, nearly twice as many patients as in the previous periods could be discharged from the hospital within 7 days; the overall 28-day mortality was significantly lower compared to that of the Delta period. It also did not differ between periods that were dominated by the BA.1 and BA.2 subvariants. The study indicates that the Omicron SARS-CoV-2 variant that dominated between January and June 2022 caused a disease which resembled the common cold, and was caused by seasonal alpha and beta-coronaviruses with a low pathogenicity for humans. However, one should note that this effect may not only have been related to biological features of the Omicron lineage, but may additionally have been driven by the increased levels of immunization through natural infections and vaccinations, for which we could not account for due to a lack of sufficient data.

Natural course of acute COVID-19 among healthy children in a tertiary hospital

BACKGROUND

Previous studies have reported the clinical and epidemiological characteristics of children with coronavirus disease 2019 (COVID-19) in a cross-sectional fashion; however, the natural course of each symptom based on a daily basis during the acute phase has not yet been clarified. This retrospective study aimed to describe the natural course of COVID-19 in children according to dominant variants.

METHODS

We conducted our study on symptomatic children with COVID-19 who were hospitalized at the National Center for Child Health and Development, in Japan. We excluded patients who were observed for less than 9 days and those with underlying disease, COVID-19 vaccination, coinfection, complications, or therapeutic intervention. We collected the data on each participant's age at admission, sex, medical history, observation period, hospitalization period, SARS-CoV-2 test results, and 10 daily symptoms in the first 9 days from the illness onset.

RESULTS

Eventually, 115 children were included in this study. The prevalence of fever during the omicron era declined more rapidly over time than that during the pre-omicron era. The prevalence of cough and rhinorrhea did not decline during the observation period, and these clinical manifestations were more common during the pre-omicron era at any point. The prevalence of dysgeusia and/or dysosmia steadily increased over time in the pre-omicron era. This study demonstrated that the prevalence of some symptoms differed not only at the onset but also over time during the acute phase.

CONCLUSION

Details of the natural clinical course of children with COVID-19 help primary care physicians to manage these patients.

Intestinal Shedding of SARS-CoV-2 in Children: No Evidence for Infectious Potential

The clinical courses of COVID-19 in children are often mild and may remain undiagnosed, but prolonged intestinal virus shedding has been documented, thus potentially enabling fecal-oral transmission. However, the infectious potential of SARS-CoV-2 viruses excreted with feces has remained unclear. Here, we investigated 247 stool specimens from 213 pediatric patients to assess the prevalence of intestinal SARS-CoV-2 shedding in hospitalized children without or with COVID-19 and determined the infectious capacity of stool-borne viruses. Upon RT-qPCR screening, the infectivity of virus-positive samples was tested in cell culture using the Vero-E6 permissive cell line. SARS-CoV-2 RNA was detected by RT-qPCR in 32 (13%) stool specimens, but the analysis of virus-positive samples in cell culture revealed no cytopathic effects attributable to SARS-CoV-2-related cell damage. Our findings do not support the notion of potential fecal-oral SARS-CoV-2 spreading, thus questioning the role of hygienic measures designed to prevent this mode of viral transmission.