Children develop robust and sustained cross-reactive spike-specific immune responses to SARS-CoV-2 infection.

SARS-CoV-2 infection is generally mild or asymptomatic in children but a biological basis for this outcome is unclear. Here we compare antibody and cellular immunity in children (aged 3-11 years) and adults. Antibody responses against spike protein were high in children and seroconversion boosted responses against seasonal Beta-coronaviruses through cross-recognition of the S2 domain. Neutralization of viral variants was comparable between children and adults. Spike-specific T cell responses were more than twice as high in children and were also detected in many seronegative children, indicating pre-existing cross-reactive responses to seasonal coronaviruses. Importantly, children retained antibody and cellular responses 6 months after infection, whereas relative waning occurred in adults. Spike-specific responses were also broadly stable beyond 12 months. Therefore, children generate robust, cross-reactive and sustained immune responses to SARS-CoV-2 with focused specificity for the spike protein. These findings provide insight into the relative clinical protection that occurs in most children and might help to guide the design of pediatric vaccination regimens.

Perceptions of adolescents on the COVID-19 pandemic and returning to school: qualitative questionnaire survey, September 2020, England.

BACKGROUND: Little is known about the views of adolescents returning to secondary school during the current COVID-19 pandemic. METHODS: In September 2020, the UK Health Security Agency (UKHSA), formerly known as Public Health England (PHE),recruited staff and students in secondary schools to provide nasal swabs, oral fluid and blood samples for SARS-CoV-2 infection and antibody testing. Students aged 11-18 years in five London schools completed a short questionnaire about their perception of the pandemic, returning to school, risk to themselves and to others and infection control measures, and participating in school testing. RESULTS: A questionnaire was completed by 64% (297/462) of participants. Students were generally not anxious at all (19.7%; 58/294) or not really anxious (40.0%; 114/295) about returning to school, although 5.4% (n = 16/295) were extremely nervous. Most students were very worried about transmitting the virus to their family (60.2%; 177/294) rather than to other students (22.0%; 65/296) or school staff (19.3%; 57/296), or catching the infection themselves (12.5%; 37/296). Students were more likely to maintain physical distancing in the presence of school staff (84.6%; 247/292) and in public places (79.5%; 233/293) but not when with other students (46.8%; 137/293) or friends (40.8%; 120/294). A greater proportion of younger students (school years 7-9; 11-14-year-olds) reported not being anxious at all than older students (school years 12-13; 16-18-year-olds) (47/174 [27.0%] vs 3/63 [4.8%]; p = 0.001). Younger students were also less likely to adhere to physical distancing measures and wear face masks. Most students reported positive experiences with SARS-CoV-2 testing in schools, with 92.3% (262/284) agreeing to have another blood test in future visits. CONCLUSIONS: Younger students in secondary schools were less concerned about catching and transmitting SARS-CoV-2 and were less likely to adhere to protective measures. Greater awareness of the potential risks of SARS-CoV-2 transmission between secondary school students potentially leading to increased risk of infection in their teachers and their household members may increase adherence to infection control measures within and outside schools.

Classification of sleep-related sudden unexpected death in infancy: A national survey.

AIM: To identify how British Child Death Overview Panels (CDOPs) and paediatric pathologists classify cause of death for sleep-related Sudden Unexpected Death in Infancy (SUDI). To determine compliance with national requirements for SUDI investigation. METHODS: Electronic survey of CDOPs and pathologists using three vignettes of SUDI cases illustrating: accidental asphyxia, typical Sudden Infant Death Syndrome (SIDS) and SIDS with co-sleeping. RESULTS: Thirty-eight (41%) of 92 CDOPs returned questionnaires, and 32 were complete. Thirteen (14%) of 90 pathologists returned complete questionnaires. Thirty-one (97%) CDOPs and 7 (53%) pathologists agreed with the cause of death in the accidental asphyxia case; 24 (75%) CDOPs and 9 (69%) pathologists in the typical SIDS case; and 11 (34%) CDOPs and 1 (8%) pathologist in the co-sleeping SIDS case. Pathologists used the terms SUDI or unascertained as the cause of death for the accidental asphyxia case (46%) and the co-sleeping SIDS case (77%). These terms were used by CDOPs for the typical SIDS case (25%) and the co-sleeping SIDS case (41%). Seventeen (46%) CDOPs reported compliance with guidelines for investigation in more than 75% of cases. CONCLUSION: There is wide variation in classification of deaths, with only limited agreement between CDOPs and pathologists. The terms SIDS and accidental asphyxia are underused, even in typical cases.

Implementation of preventive measures to prevent COVID-19: a national study of English primary schools in summer 2020.

We examined the feasibility of implementing preventive measures to prevent SARS-CoV-2 transmission across 105 English primary schools in summer 2020 via a survey and interviews with headteachers. High rates of implementation of most recommended measures were noted with the exception of requiring 2 m distance for students, fitting hand sanitizers in classrooms and introducing one-way systems in school corridors. Measures such as regular handwashing and stopping assemblies were considered easy to implement. Majorly challenging measures included distancing between individuals (for students: 51%, N = 99; for staff: 34%; N = 98; for parents: 26%, N = 100), spacing out desks (34%, N = 99), keeping same staff assigned to each student group (33%, N = 97) and staggering break times (25%, N = 99). Rapid implementation was facilitated by staff commitment and communication among stakeholders, but hampered by limitations with guidance received, physical environments, resources, parental adherence and balancing preventive measures with learning. Difficulties with distancing for younger children suggest that smaller bubbles with fewer distancing requirements within these may be a policy option. Schools require further financial, human resource and other support for effective implementation of preventive measures.

Improving engagement with services to prevent Sudden Unexpected Death in Infancy (SUDI) in families with children at risk of significant harm: A systematic review of evidence.

This paper reports part of a wider systematic review commissioned by the English National Safeguarding Panel on Sudden Unexpected Death in Infancy (SUDI). The wider review covered three areas: interventions to improve safer sleep practices in high-risk families, interventions to improve engagement with services and decision making by parents at high risk of SUDI about infant sleep environments. Here, we report the qualitative and quantitative studies reviewed under the engagement strand. Parental engagement is understood to be a multidimensional task for health and social care professionals comprising attitudinal, relational and behavioural components. Following a PROSPERO registered systematic review synthesizing the three strands outlined, 28 papers were found to be relevant in the review of interventions to improve engagement with services in families with children at risk of significant harm through abuse or neglect. No studies were found that specifically focused on engagement of families at high risk for SUDI, so these wider engagement studies were included. The different types of intervention reported in the included studies are described under two broad themes: Enablers (including parental motivation and working with families) and Barriers. Given the focus in the studies on interventions that support parental engagement, the Enablers theme is more extensive than the Barriers reported although all studies noted well-understood barriers. The evidence underpinning these interventions and approaches are reviewed in this paper. We conclude that effective engagement is facilitated by experienced professionals given time to develop supportive non-judgemental relationships with families in their homes, working long-term, linking with communities and other services. While these conclusions have been drawn from wider studies aimed at reducing child maltreatment, we emphasize lessons to be drawn for SUDI prevention work with families with children at risk of significant harm.

Rigour and Rapport: a qualitative study of parents' and professionals' experiences of joint agency infant death investigation.

BACKGROUND: In many countries there are now detailed Child Death Review (CDR) processes following unexpected child deaths. CDR can lead to a fuller understanding of the causes for each child's death but this potentially intrusive process may increase the distress of bereaved families. In England, a joint agency approach (JAA) is used where police, healthcare and social services investigate sudden child deaths together and a key part of this is the joint home visit (JHV) where specialist police and paediatricians visit the home with the parents to view the scene of death. This study aimed to learn of bereaved parents' experiences of JAA investigation following Sudden Unexpected Death in Infancy (SUDI). METHODS: This was a qualitative study of joint agency investigation of SUDI by specialist police, healthcare and social services including case note analysis, parental questionnaires, and in-depth interviews with parents and professionals. Families were recruited at the conclusion of the JAA. Data were analysed using a Framework Approach. RESULTS: 21/113 eligible families and 26 professionals participated giving theoretical saturation of data. There was an inherent conflict for professionals trying to both investigate deaths thoroughly as well as support families. Bereaved parents appreciated the JAA especially for the information it provided about the cause of death but were frustrated with long delays waiting to obtain this. Many parents wanted more emotional support to be routinely provided. Most parents found the JHV helpful but a small minority of mothers found this intensely distressing. In comparison to JHVs, when police visited death scenes without paediatricians, information was missed and parents found these visits more upsetting. There were issues with uniformed non-specialist police traumatising parents by starting criminal investigations and preventing parents from accessing their home or collecting vital possessions. CONCLUSIONS: Overall most parents feel supported by professionals during the JAA; however there is scope for improvement. Paediatricians should ensure that parents are kept updated with the progress of the investigations. Some parents require more emotional support and professionals should assist them in accessing this.

Unintentional asphyxia, SIDS, and medically explained deaths: a descriptive study of outcomes of child death review (CDR) investigations following sudden unexpected death in infancy.

BACKGROUND: A comprehensive child death review (CDR) program was introduced in England and Wales in 2008, but as yet data have only been analyzed at a local level, limiting the learning from deaths. The aim of this study is to describe the profile of causes and risk factors for sudden unexpected death in infancy (SUDI) as determined by the new CDR program. METHODS: This was a descriptive outcome study using data from child death overview panel Form C for SUDI cases dying during 2010-2012 in the West Midlands region of England. The main outcome measures were: cause of death, risk factors and potential preventability of death, and determination of deaths probably due to unintentional asphyxia. RESULTS: Data were obtained for 65/70 (93 %) SUDI cases. 20/65 (31 %) deaths were initially categorized as due to medical causes; 21/65 (32 %) as SIDS; and 24/65 (37 %) as undetermined. Reanalysis suggested that 2/21 SIDS and 7/24 undetermined deaths were probably due to unintentional asphyxia, with 6 of these involving co-sleeping and excessive parental alcohol consumption. Deaths classified as "undetermined" had significantly higher total family and environmental risk factor scores (mean 2.6, 95 % CI 2.0-3.3) compared to those classified as SIDS (mean 1.6, 95 % CI 1.2-1.9), or medical causes for death (mean 1.1, 95 % CI 0.8-1.3). 9/20 (47 %) of medical deaths, 19/21 (90 %) SIDS, and 23/24 (96 %) undetermined deaths were considered to be potentially preventable. There were inadequacies in medical provision identified in 5/20 (25 %) of medically explained deaths. CONCLUSIONS: The CDR program results in detailed information about risk factors for SUDI cases but failed to recognize deaths probably due to unintentional asphyxia. The misclassification of probable unintentional asphyxial deaths and SIDS as "undetermined deaths" is likely to limit learning from these deaths and inhibit prevention strategies. Many SUDI occurred in families with mental illness, substance misuse and chaotic lifestyles and most in unsafe sleep environments. This knowledge could be used to better target safe sleep advice for vulnerable families and prevent SUDI in the future.

An evidence-based guide to the investigation of sudden unexpected death in infancy.

PURPOSE: Many countries now have detailed investigations following sudden unexpected death in infancy (SUDI) but there is no clear evidence as to the most effective way to investigate SUDI. This systematic literature review addresses the following questions: What are the current models of practice for investigating SUDI? What is the evidence to support these investigative models? What are the key factors for effective SUDI investigation? METHODS: This was a systematic review of papers from Europe, North America, and Australasia, detailing models of SUDI investigation or the outcomes of SUDI investigations. RESULTS: The review includes data detailing four different models of investigation: police-led, coroner or medical examiner-led, healthcare-led or joint agency approach models. There were 18 different publications providing evidence of effectiveness of these models. All models, with the exception of police-led models, have the potential to reach best practice standards for SUDI investigation. Key factors identified for effective SUDI investigation include the need for mandatory investigation, strong leadership, integration with coronial services, and for investigations to be provided by specialist professionals. CONCLUSION: Detailed SUDI investigation should lead to greater understanding of why infants die and should help prevent future deaths. The challenge is now to ensure that local SUDI investigative practices are as effective as possible.

What do bereaved parents want from professionals after the sudden death of their child: a systematic review of the literature.

BACKGROUND: The death of a child is a devastating event for parents. In many high income countries, following an unexpected death, there are formal investigations to find the cause of death as part of wider integrated child death review processes. These processes have a clear aim of establishing the cause of death but it is less clear how bereaved families are supported. In order to inform better practice, a literature review was undertaken to identify what is known about what bereaved parents want from professionals following an unexpected child death. METHODS: This was a mixed studies systematic review with a thematic analysis to synthesize findings. The review included papers from Europe, North America or Australasia; papers had to detail parents' experiences rather than professional practices. RESULTS: The review includes data from 52 papers, concerning 4000 bereaved parents. After a child has died, parents wish to be able to say goodbye to them at the hospital or Emergency Department, they would like time and privacy to see and hold their child; parents may bitterly regret not being able to do so. Parents need to know the full details about their child's death and may feel that they are being deliberately evaded when not given this information. Parents often struggle to obtain and understand the autopsy results even in the cases where they consented for the procedure. Parents would like follow-up appointments from health care professionals after the death; this is to enable them to obtain further information as they may have been too distraught at the time of the death to ask appropriate questions or comprehend the answers. Parents also value the emotional support provided by continuing contact with health-care professionals. CONCLUSION: All professionals involved with child deaths should ensure that procedures are in place to support parents; to allow them to say goodbye to their child, to be able to understand why their child died and to offer the parents follow-up appointments with appropriate health-care professionals.

Infant death from accidental suffocation and strangulation in bed in England and Wales: rare or unrecognised events?

BACKGROUND: Mandatory joint police and healthcare investigations of sudden unexpected death in infancy (SUDI) have been in place since 2008 in England. These include death scene examination with cause of death determined at multiprofessional case conference. Detailed evidence on sleep arrangements is available for most cases potentially leading to more being identified as due to accidental suffocation. SUDI remaining unexplained following investigation are classified as SIDS (sudden infant death syndrome) or unspecified deaths.Our objective was to determine whether detailed SUDI investigation has led to an increase in deaths classified as accidental suffocation or strangulation in bed (ASSB)? METHODS: We obtained official mortality data for England and Wales for infants dying aged 0-364 days for International Statistical Classification of Diseases and Related Health Problems, 10th revision codes R95 (SIDS), R96, R98, R99 (unspecified causes of mortality) and W75 (ASSB) for the years 2000-2019.We calculated the mortality rate for ASSB, SIDS and unspecified causes based on total live births each year. RESULTS: Unexplained SUDI decreased from 353 in 2000 to 175 in 2019, with the mortality rate falling from 0.58 to 0.29 per 1000 live births. The total postneonatal mortality rate fell during this time from 1.9 to 0.9 per 1000 live births suggesting this is a genuine fall. SIDS accounted for 70% of unexplained SUDI in 2000 falling to 49% in 2020 with a corresponding increase in R99 unspecified deaths.Few deaths were recorded as ASSB (W75), ranging between 4 in 2010 and 24 in 2001. The rate for ASSB ranged from 0.6 to 4.0 per 100000 live births. CONCLUSIONS: There is a shift away from SIDS (R95) towards unspecified causes of death (R96, R98, R99). Improved investigation of deaths has not led to increased numbers of death identified as due to ASSB. There needs to be clear guidelines on accurate classification of deaths from ASSB to facilitate learning from deaths and inform prevention efforts.

Kinship Care and Child Protection in High-Income Countries: A Scoping Review.

Kinship care is a global phenomenon with a long history, which in high-income countries (HICs) at least, is being increasingly formalized through legislation and policy. There are many benefits to kinship care, including improved child mental health and well-being when compared to other types of out-of-home care. Despite this, kinship care is not without its risks with a lack of support and training for kinship carers putting children at an increased risk of abuse and neglect. This scoping review was conducted across 11 databases to explore the breadth and depth of the literature about abuse and neglect within kinship care in HICs and to provide initial indications about the relationship between kinship care and abuse. Of the 2,308 studies initially identified, 26 met the inclusion criteria. A majority of studies were from the United States, and most used case review methods. From the included studies, rates of re-abuse, and particularly rates of physical and sexual abuse, appear to be lower in kinship care settings when compared to other out-of-home care settings, but rates of neglect are often higher. This review has demonstrated that a small but significant number of children living in kinship care experience neglect or abuse.

Improving professional practice in the investigation and management of intrafamilial child sexual abuse: Qualitative analysis of serious child protection reviews.

BACKGROUND: Local multi-agency case reviews are regularly held in England when children have suffered significant harm from abuse or neglect, including from child sexual abuse (CSA). Most CSA takes place within families, is common but under-reported and can cause long-term harm. OBJECTIVE: The aim was to analyse English child protection reviews relating to intrafamilial CSA to identify improvements for professional practice. PARTICIPANTS AND SETTING: Local Child Safeguarding Practice Reviews (LCSPRs) and Serious Case Reviews (SCRs) relating to serious incidents of intrafamilial CSA occurring between 01 April 2017 and 31 March 2020. METHODS: LCSPRs and SCRs were obtained from the National Case Review Repository and thematically analysed. RESULTS: There were 243 reviews, of which 25 featured intrafamilial CSA. The main themes related to perpetrators, vulnerable families, and professional practice. Half of perpetrators were known by services to have previously abused children, but issues with professional practice enabled them to continue. Most children did not disclose CSA verbally showing challenging or sexualised behaviour; but professionals lacked knowledge and confidence on how to intervene without verbal disclosure, which limited safeguarding actions. Non-engagement by families with services was common, with some non-abusing parents complicit in abuse and deception. Significant neglect occurred in half the families, which diverted professional attention away from CSA. CONCLUSION: CSA is deliberate abuse of children involving considerable deception by perpetrators in contrast to some other types of child abuse. This difference in abuser behaviour makes child protection more difficult, particularly when professionals do not recognise and respond to children's non-verbal disclosures.

Nasal mucosal IgA levels against SARS-CoV-2 and seasonal coronaviruses are low in children but boosted by reinfection.

Repeated coronavirus infections in childhood drive progressive maturation of systemic immune responses into adulthood. Analyses of immune responses in children have focused primarily upon systemic assessment but the importance of mucosal immunity is increasingly recognised. We studied virus-specific antibody responses in contemporaneous nasal swabs and blood samples from 99 children (4-15 years) and 28 adults (22-56 years), all of whom had prior SARS-CoV-2 infection. Whilst mucosal IgA titres against Influenza and Respiratory Syncytial virus were comparable between children and adults, those against all coronaviruses, including SARS-CoV-2, were lower in children. Mucosal IgA antibodies demonstrated comparable relative neutralisation capacity in both groups and retained activity against recent omicron variants such as XBB.1 which are highly evasive of IgG neutralisation. SARS-CoV-2 reinfection preferentially enhanced mucosal IgA responses whilst the impact of vaccination was more modest. Nasal IgA levels against coronaviruses thus display a pattern of incremental response to reinfection which likely determines the natural history of reinfection. This highlights the particular significance of developing mucosal vaccines against coronaviruses in children.

Antibody Persistence After Primary SARS-CoV-2 Infection and Protection Against Future Variants Including Omicron in Adolescents: National, Prospective Cohort Study.

BACKGROUND: Antibodies are a measure of immunity after primary infection, which may help protect against further SARS-CoV-2 infections. They may also provide some cross-protection against SARS-CoV-2 variants. There are limited data on antibody persistence and, especially, cross-reactivity against different SARS-CoV-2 variants after primary infection in children. METHODS: We initiated enhanced surveillance in 18 secondary schools to monitor SARS-CoV-2 infection and transmission in September 2020. Students and Staff provided longitudinal blood samples to test for variant-specific SARS-CoV-2 antibodies using in-house receptor binding domain assays. We recruited 1189 students and 1020 staff; 160 (97 students, 63 staff) were SARS-CoV-2 nucleocapsid-antibody positive at baseline and had sufficient serum for further analysis. RESULTS: Most participants developed sustained antibodies against their infecting [wild-type (WT)] strain as well as cross-reactive antibodies against the Alpha, Beta and Delta variants but at lower titers than WT. Staff had significantly lower antibodies titers against WT as cross-reactive antibodies against the Alpha, Beta and Delta variants than students (all P < 0.01). In participants with sufficient sera, only 2.3% (1/43) students and 17.2% (5/29) staff had cross-reactive antibodies against the Omicron variant; they also had higher antibody titers against WT (3042.5; 95% confidence interval: 769.0-12,036.2) than those who did not have cross-reactive antibodies against the Omicron variant (680.7; 534.2-867.4). CONCLUSIONS: We found very high rates of antibody persistence after primary infection with WT in students and staff. Infection with WT induced cross-reactive antibodies against Alpha, Beta and Delta variants, but not Omicron. Primary infection with WT may not be cross-protective against the Omicron variant.

Immunological imprinting of humoral immunity to SARS-CoV-2 in children.

Omicron variants of SARS-CoV-2 are globally dominant and infection rates are very high in children. We measure immune responses following Omicron BA.1/2 infection in children aged 6-14 years and relate this to prior and subsequent SARS-CoV-2 infection or vaccination. Primary Omicron infection elicits a weak antibody response with poor functional neutralizing antibodies. Subsequent Omicron reinfection or COVID-19 vaccination elicits increased antibody titres with broad neutralisation of Omicron subvariants. Prior pre-Omicron SARS-CoV-2 virus infection or vaccination primes for robust antibody responses following Omicron infection but these remain primarily focussed against ancestral variants. Primary Omicron infection thus elicits a weak antibody response in children which is boosted after reinfection or vaccination. Cellular responses are robust and broadly equivalent in all groups, providing protection against severe disease irrespective of SARS-CoV-2 variant. Immunological imprinting is likely to act as an important determinant of long-term humoral immunity, the future clinical importance of which is unknown.

Use of melatonin: a single-centre audit.

Sleep disorders in childhood are common. Melatonin is prescribed by UK community paediatricians to treat sleep disorders, but practice is not standardised. This audit reviewed melatonin prescribing within a community paediatric department in a 12-month period. 682 children received melatonin prescriptions; a random sample of 198 records were reviewed. The most common underlying condition was autism spectrum disorder (ASD) in 28%. 41% had no underlying diagnosis when melatonin was initiated and were waiting for neurodevelopmental/ASD assessment. 42% were on melatonin for at least 2 years. Further work is required to optimise melatonin prescribing practice for children and young people.

EarLy Surveillance for Autoimmune diabetes: protocol for a qualitative study of general population and stakeholder perspectives on screening for type 1 diabetes in the UK (ELSA 1).

OBJECTIVE: Type 1 diabetes (T1D) is the most common form of diabetes in children, accounting for 96% of cases, with 29 000 children affected in the UK. Studies have recently identified immunotherapies that safely delay the development of T1D for at least 3 years, and further therapies are in development. General population screening programs in other countries can now accurately identify children with presymptomatic T1D who can be entered into prevention studies. The UK does not have such a system in place. We aim to explore whether parents and children in the UK would want to be part of such a program of testing for T1D in the general population, how they would want to be informed and participate in such a program, and how any barriers to recruitment and participation can be addressed. Additionally, the views of stakeholders who would be involved in the testing program will be collected and analyzed. RESEARCH DESIGN AND METHODS: We will interview parents/guardians and children aged 3-13 years about their views on screening for T1D. We will recruit purposefully to ensure representation across ethnicities and socioeconomic groups. Interviews will be transcribed, analyzed and used to inform iterative co-design work with additional families to address any issues raised. Similar qualitative work will be undertaken with professional stakeholders who would be involved in implementing any future screening program. Where possible, all aspects of this study will be performed remotely by phone or online to minimize infection risk. CONCLUSIONS: This qualitative study will provide the first insights into acceptability of testing and monitoring for T1D in the general population from the perspective of families and stakeholders in the UK. Co-design work will help establish the barriers and identify strategies to mitigate and overcome these issues, as an important step towards consideration of national testing for T1D.

Parents' and teachers' attitudes to and experiences of the implementation of COVID-19 preventive measures in primary and secondary schools following reopening of schools in autumn 2020: a descriptive cross-sectional survey.

OBJECTIVE: To assess implementation and ease of implementation of control measures in schools as reported by staff and parents. DESIGN: A descriptive cross-sectional survey. SETTING: Staff and parents/guardians of the 132 primary schools and 19 secondary schools participating in COVID-19 surveillance in school kids (sKIDs and sKIDsPLUS Studies). MAIN OUTCOME MEASURE: Prevalence of control measures implemented in schools in autumn 2020, parental and staff perception of ease of implementation. RESULTS: In total, 56 of 151 (37%) schools participated in this study, with 1953 parents and 986 staff members completing the questionnaire. Most common measures implemented by schools included regular hand cleaning for students (52 of 56, 93%) and staff (70 of 73, 96%), as reported by parents and staff, respectively, and was among the easiest to implement at all times for students (57%) and even more so, for staff (78%). Maintaining 2-metre distancing was less commonly reported for students (24%-51%) as it was for staff (81%-84%), but was one of the most difficult to follow at all times for students (25%) and staff (16%) alike. Some measures were more commonly reported by primary school compared to secondary school parents, including keeping students within the same small groups (28 of 41, 68% vs 8 of 15, 53%), ensuring the same teacher for classes (29 of 41, 71% vs 6 of 15, 40%). On the other hand, wearing a face covering while at school was reported by three-quarters of secondary school parents compared with only parents of 4 of 41 (10%) primary schools. Other measures such as student temperature checks (5%-13%) and advising staff work from home if otherwise healthy (7%-15%) were rarely reported. CONCLUSIONS: Variable implementation of infection control measures was reported, with some easier to implement (hand hygiene) than others (physical distancing).

SARS Antibody Testing in Children: Development of Oral Fluid Assays for IgG Measurements.

Seroepidemiological studies to monitor antibody kinetics are important for assessing the extent and spread of SARS-CoV-2 in a population. Noninvasive sampling methods are advantageous for reducing the need for venipuncture, which may be a barrier to investigations, particularly in pediatric populations. Oral fluids are obtained by gingiva-crevicular sampling from children and adults and are very well accepted. Enzyme immunoassays (EIAs) based on these samples have acceptable sensitivity and specificity compared to conventional serum-based antibody EIAs and are suitable for population-based surveillance. We describe the development and evaluation of SARS-CoV-2 IgG EIAs using SARS-CoV-2 viral nucleoprotein (NP) and spike (S) proteins in IgG isotype capture format and an indirect receptor-binding-domain (RBD) IgG EIA, intended for use in children as a primary endpoint. All three assays were assessed using a panel of 1,999 paired serum and oral fluids from children and adults participating in school SARS-CoV-2 surveillance studies during and after the first and second pandemic wave in the United Kingdom. The anti-NP IgG capture assay was the best candidate, with an overall sensitivity of 75% (95% confidence interval [CI]: 71 to 79%) and specificity of 99% (95% CI: 78 to 99%) compared with paired serum antibodies. Sensitivity observed in children (80%, 95% CI: 71 to 88%) was higher than that in adults (67%, CI: 60% to 74%). Oral fluid assays (OF) using spike protein and RBD antigens were also 99% specific and achieved reasonable but lower sensitivity in the target population (78%, 95% CI [68% to 86%] and 53%, 95% CI [43% to 64%], respectively). IMPORTANCE We report on the first large-scale assessment of the suitability of oral fluids for detection of SARS-CoV-2 antibody obtained from healthy children attending school. The sample type (gingiva-crevicular fluid, which is a transudate of blood but is not saliva) can be self collected. Although detection of antibodies in oral fluids is less sensitive than that in blood, our study suggests an optimal format for operational use. The laboratory methods we have developed can reliably measure antibodies in children, who are able to take their own samples. Our findings are of immediate practical relevance for use in large-scale seroprevalence studies designed to measure exposure to infection, as they typically require venipuncture. Overall, our data indicate that OF assays based on the detection of SARS-CoV-2 antibodies are a tool suitable for population-based seroepidemiology studies in children and highly acceptable in children and adults, as venipuncture is no longer necessary.

Emergence of the delta variant and risk of SARS-CoV-2 infection in secondary school students and staff: Prospective surveillance in 18 schools, England.

BACKGROUND: The role of educational settings in SARS-CoV-2 infection and transmission remains controversial. We investigated SARS-CoV-2 infection, seroprevalence, and seroconversion rates in secondary schools during the 2020/21 academic year, which included the emergence of the more transmissible alpha and delta variants, in England. METHODS: The UK Health Security Agency (UKHSA) initiated prospective surveillance in 18 urban English secondary schools. Participants had nasal swabs for SARS-CoV-2 RT-PCR and blood sampling for SARS-CoV-2 nucleoprotein and spike protein antibodies at the start (Round 1: September-October 2020) and end (Round 2: December 2020) of the autumn term, when schools reopened after national lockdown was imposed in January 2021 (Round 3: March-April 2021), and end of the academic year (Round 4: May-July 2021). FINDINGS: We enrolled 2314 participants (1277 students, 1037 staff; one participant had missing data for PCR testing). In-school testing identified 31 PCR-positive participants (20 students, 11 staff). Another 247 confirmed cases (112 students, 135 staff) were identified after linkage with national surveillance data, giving an overall positivity rate of 12.0% (278/2313; staff: 14.1%, 146/1037 vs students: 10.3%, 132/1276; p = 0.006). Trends were similar to national infection data. Nucleoprotein-antibody seroprevalence increased for students and staff between Rounds 1 and 3 but were similar between Rounds 3 and 4, when the delta variant was the dominant circulating strain. Overall, Nucleoprotein-antibody seroconversion was 18.4% (137/744) in staff and 18.8% (146/778) in students, while Spike-antibody seroconversion was higher in staff (72.8%, 525/721) than students (21.3%, 163/764) because of vaccination. INTERPRETATION: SARS-CoV-2 infection rates in secondary schools remained low when community infection rates were low, even as the delta variant was emerging in England. FUNDING: This study was funded by the UK Department of Health and Social Care.