Humoral responses to SARS-CoV-2 infection in children

SUMMARY

Rationale: Coronavirus disease 2019 (COVID-19) first started in China in December 2019 and the outbreak was declared a pandemic by the World Health Organization (WHO) on 11 March 2020. Sero-epidemiological studies can identify patients that have been infected with SARS-CoV2, regardless of the severity of their illness. These studies are needed to provide estimates of herd immunity that are essential for public health policy makers. The antibody response is crucial for preventing viral infections and may also contribute to combat infection. The first seroepidemiological studies in adults in the Netherlands are being initiated, but there is currently no data on immunity in children. Evidence is emerging that while children suffer less severely from COVID-19, they do get infected, can spread the virus, and elicit IgG, IgM, IgA or secretory IgA responses. Differences in the humoral response to SARS-CoV2 in between children and adults may partly explain the difference in disease severity.
Objective: To evaluate circulatory and mucosal antibody responses against SARS-CoV2 in children during the COVID-19 outbreak in the Netherlands.

Study design: Multicenter prospective cohort study

Study population: Children younger than 18 years of age in whom blood is drawn for routine medical care in one of the participating hospitals are eligible for participation.

Main study parameters/endpoints: IgG, IgM, IgA and total neutralizing antibodies against SARS-CoV2 in blood and secretory IgA levels against SARS-CoV2 in saliva from all participants

Nature and extent of the burden and risks associated with participation, benefit and group relatedness:
This study is classified as an observational study in subjects under 18 years of age. We will ask additional blood to be collected if the patient has blood tests ordered by the treating physician in routine medical care. The child will not be subjected to additional dermal or vena punctures for this study. Blood can be obtained when the child presents to the emergency department, during hospitalization, or in the outpatient clinic of the participating hospitals. We will ask for an additional 1 ml of blood in children aged 0-1 years, 2 ml in 1-5 year olds, and 5 ml in 5-18 year olds. Simultaneously, a saliva sample with a buccal swab will be sampled. The burden to participate in this study is therefore negligible. Parents/guardians can join their child at all times during the procedure.
The individual study results will be shared with the parents/guardians after finalizing the study.

Children will show circulatory and mucosal antibody responses against SARS-CoV2 even when not having experienced clinical symptoms of COVID19.

Blood :
Neutralizing antibodies (IgG, IgA and IgM) : via neutralization assay.
IgG and IgM against SARS-CoV2: via ELISA
Saliva:
Secretory total IgA and specific secretory IgA against SARS-CoV2: via ELISA.

All these measurements will be performed between september 2020 and january 2021

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