Evolving infectious disease dynamics shape school-based intervention effectiveness.

School-based interventions during epidemics are often controversial, as experienced during the COVID-19 pandemic, where reducing transmission had to be weighed against the adverse effects on young children. However, it remains unclear how the broader epidemiologic context influences the effectiveness of these interventions and when they should be implemented. Through integrated modeling of epidemiological and genetic data from a longitudinal school-based surveillance study of SARS-CoV-2 in 2021-2022 (N children = 336, N adults = 51) and scenario simulations, we show how transmission dynamics in schools changed markedly due to strong increases in community-acquired infections in successive periods of viral variants, ultimately undermining the potential impact of school-based interventions in reducing infection rates in the school-aged population.

SARS-CoV-2 convalescence and hybrid immunity elicits mucosal immune responses.

Background: Mucosal antibodies play a key role in the protection against SARS-CoV-2 infection in the upper respiratory tract, and potentially in limiting virus replication and therefore onward transmission. While systemic immunity to SARS-CoV-2 is well understood, we have a limited understanding about the antibodies present on the nasal mucosal surfaces.

Methods: In this study, we evaluated SARS-CoV-2 mucosal antibodies following previous infection, vaccination, or a combination of both.

Clinical sensitivity and specificity of a high-throughput microfluidic nano-immunoassay combined with capillary blood microsampling for the identification of anti-SARS-CoV-2 Spike IgG serostatus.

Objectives: We evaluate the diagnostic performance of dried blood microsampling combined with a high-throughput microfluidic nano-immunoassay (NIA) for the identification of anti-SARS-CoV-2 Spike IgG seropositivity.

Methods: We conducted a serological study among 192 individuals with documented prior SARS-CoV-2 infection and 44 SARS-CoV-2 negative individuals. Participants with prior SARS-CoV-2 infection had a long interval of 11 months since their qRT-PCR positive test.

Epidemiological, virological and serological investigation of a SARS-CoV-2 outbreak (Alpha variant) in a primary school: A prospective longitudinal study.

Objectives: To report a prospective epidemiological, virological and serological investigation of a SARS-CoV-2 outbreak in a primary school.

Methods: As part of a longitudinal, prospective, school-based surveillance study, this investigation involved repeated testing of 73 pupils, 9 teachers, 13 non-teaching staff and 26 household members of participants who tested positive, with rapid antigen tests and/or RT-PCR (Day 0-2 and Day 5-7), serologies on dried capillary blood samples (Day 0-2 and Day 30), contact tracing interviews and SARS-CoV-2 whole genome sequencing.

Results: We identified 20 children (aged 4 to 6 years from 4 school classes), 2 teachers and a total of 4 household members who were infected by the Alpha variant during this outbreak.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Viral Load Kinetics in Symptomatic Children, Adolescents, and Adults.

SARS-CoV-2 viral load (VL) can serve as a correlate for infectious virus presence and transmission. Viral shedding kinetics over the first week of illness for symptomatic children (n = 279), adolescents (n = 639), and adults (n = 7109) show VLs compatible with infectious virus presence, with slightly lower VL in children than adults.

Cerebrospinal Fluid Features in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Reverse Transcription Polymerase Chain Reaction (RT-PCR) Positive Patients.

This study analyzed the cerebrospinal fluid features of 31 coronavirus disease 2019 (COVID-19) patients with neurological complications. We observed neither severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the cerebrospinal fluid, nor intrathecal immunoglobulin G (IgG) synthesis but did observe signs of blood-brain barrier disruption. These results might serve as a basis for a better understanding of SARS-CoV-2 related neuropathogenesis.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Viral Load in the Upper Respiratory Tract of Children and Adults With Early Acute Coronavirus Disease 2019 (COVID-19).

The factors that contribute to transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by children are unclear. We analyzed viral load at the time of diagnosis in 53 children and 352 adults with coronavirus disease 2019 (COVID-19) in the first 5 days post symptom onset. No significant differences in SARS-CoV-2 RNA loads were seen between children and adults.