The seroprevalence of SARS-CoV-2-specific antibodies in Australian children: a cross sectional study (preprint)

Background: Following reduction of public health and social measures concurrent with SARS-CoV-2 Omicron emergence in late 2021 in Australia, COVID-19 case notification rates rose rapidly. As rates of direct viral testing and reporting dropped, true infection rates were most likely to be underestimated. Objective: To better understand infection rates and immunity in this population, we aimed to estimate SARS-CoV-2 seroprevalence in Australians aged 0-19 years. Methods: We conducted a national cross sectional serosurvey from June 1, 2022, to August 31, 2022, in children aged 0-19 years undergoing an anesthetic procedure at eight tertiary pediatric hospitals. Participant questionnaires were administered, and blood samples tested using the Roche Elecsys Anti-SARS-CoV-2 total spike and nucleocapsid antibody assays. S and N seroprevalence adjusted for geographic and socioeconomic imbalances in the participant sample compared to the Australian population was estimated using multilevel regression and poststratification within a Bayesian framework. Results: Blood was collected from 2,046 participants (median age: 6.6 years). Adjusted seroprevalence of spike-antibody was 92.1 % (95% credible interval (CrI) 91.0-93.3%) and nucleocapsid-antibody was 67.0% (95% CrI 64.6-69.3). In unvaccinated children spike and nucleocapsid antibody seroprevalences were 84.2% (95% CrI 81.9-86.5) and 67.1% (95%CrI 64.0-69.8), respectively. Seroprevalence increased with age but was similar across geographic distribution and socioeconomic quintiles. Conclusion: Most Australian children and adolescents aged 0-19 years, across all jurisdictions were infected with SARS-CoV-2 by August 2022, suggesting rapid and uniform spread across the population in a very short time period. High seropositivity in unvaccinated children informed COVID-19 vaccine recommendations in Australia. Funding: Australian Government Department of Health and Aged Care.

Early childhood education and care (ECEC) had sustained benefits for young children’s vocabulary, communication, problem solving, and personal-social development during COVID-19, particularly for those from socioeconomically disadvantaged backgrounds. (preprint)

Early childhood education and care (ECEC) settings faced significant disruption during the COVID-19 pandemic, compromising the continuity, stability, and quality of provision. Two and half years on from the first UK lockdown as pandemic-era preschoolers enter formal schooling, families, practitioners, and policymakers are concerned about the impact of the disruption on children’s cognitive and socioemotional development, especially those from socioeconomically disadvantaged backgrounds. Using parent-report data from 171 children aged between 5 and 23 months in Spring 2020 (M=15 months) living in the UK, we investigate whether previously attested positive associations between ECEC attendance and the development of language and executive functions was maintained as early years settings navigated operational challenges over the first full year of the pandemic. In response to concerns about school readiness, we analyse the relationship between ECEC attendance and children’s communication, problem-solving, and personal-social development. ECEC was associated with greater growth in receptive vocabulary over the 12-month period, regardless of children’s socioeconomic background. ECEC was also associated with greater growth in expressive vocabulary, but only in children from less advantaged backgrounds. Our data suggest a similarly positive association between ECEC attendance and the communication and problem-solving skills of children from lower socioeconomic (SES) backgrounds, and between ECEC and the personal-social development of all children. We found no effect of SES or ECEC attendance on growth of either of our measures of executive function. Overall, results suggest that ECEC had sustained learning benefits for young children growing up during the pandemic despite ongoing disruption to settings, and also had specific benefits for children from less affluent home environments. As children progress to primary school, we discuss the importance of adjusting the expectations placed on pandemic-era children, and adapting curricula and learning conditions to enable schools and families to make the most of learning opportunities.

Towards a dimensional model of risk and protective factors influencing children’s early cognitive, social and emotional development during the COVID-19 pandemic (preprint)

Variation in infants’ home environment is implicated in their cognitive and psycho-social development. The pandemic has intensified variations in home environments through exacerbating socioeconomic inequalities, and increasing psychological stressors for some families. This study investigates the effects of parental (predominantly maternal) mental health, enriching activities and screen use on 280 24- to 52-month-olds’ executive functions, internalising and externalising problems, and pro-social behaviour; with socioeconomic status and social support as contextual factors. Our results indicate that aspects of the home environment are differentially associated with children’s cognitive and psycho-social development. Parents who experienced sustained mental distress during the pandemic tended to report higher child externalising and internalising problems, and executive function difficulties at follow-up. Children who spent more time engaged in enriching activities with their parents showed stronger executive functions and social competence six months later. Screen use levels during the first year of the pandemic were not associated with outcomes. To mitigate the risk of persistent negative effects for this ‘pandemic generation’ of infants, our study highlights the importance of supporting parents’ mental health. As our results demonstrate the impact of social support on mental health, investing in support services and interventions promoting building support networks are likely to be beneficial.

Early Childhood Education and Care (ECEC) during COVID-19 boosts growth in language and executive function (preprint)

High-quality, centre-based education and care during the early years benefits cognitive development, especially in children from disadvantaged backgrounds. During the COVID-19 pandemic and its associated lockdowns, access to early childhood education and care (ECEC) was disrupted. We investigate how this period affected the developmental advantages typically offered by ECEC. Using parent-report data from 189 families living in the UK, we explore associations between time spent in ECEC by 8-to-36-month-olds, their socioeconomic background, and their growth in language and executive functions between Spring and Winter 2020. Receptive vocabulary growth was greater in children who continued to attend ECEC during the period, with a stronger positive effect for children from less advantaged backgrounds. Growth of cognitive executive functions was boosted by ECEC attendance during the period, regardless of socioeconomic background. Our findings highlight the importance of high-quality ECEC for the development of key skills and for levelling socioeconomic inequalities.