A Public Health Antibody Screening Indicates a 6-Fold Higher SARS-CoV-2 Exposure Rate than Reported Cases in Children.

Abstract

BACKGROUND:

Antibody responses to virus reflect exposure and potential protection.

METHODS:

We developed a highly specific and sensitive approach to measuring antibodies against SARS-CoV-2 for population-scale immune surveillance. Antibody positivity was defined as a dual-positive response against both the receptor-binding domain and nucleocapsid proteins of SARS-CoV-2. Antibodies were measured by immunoprecipitation assays in capillary blood from 15,771 children aged 1 to 18 years living in Bavaria, Germany, and participating in a public health type 1 diabetes screening program (ClinicalTrials.gov: NCT04039945), in 1,916 dried blood spots from neonates in a Bavarian screening study (ClinicalTrials.gov: NCT03316261), and in 75 SARS-CoV-2-positive individuals. Virus positive incidence was obtained from the Bavarian health authority data.

FINDINGS:

Dual-antibody positivity was detected in none of the 3,887 children in 2019 (100% specificity) and 73 of 75 SARS-CoV-2-positive individuals (97.3% sensitivity). Antibody surveillance in children during 2020 resulted in frequencies of 0.08% in January to March, 0.61% in April, 0.74% in May, 1.13% in June, and 0.91% in July. Antibody prevalence from April 2020 was 6-fold higher than the incidence of authority-reported cases (156 per 100,000 children), showed marked variation between the seven Bavarian regions (p < 0.0001), and was not associated with age or sex. Transmission in children with virus-positive family members was 35%. 47% of positive children were asymptomatic. No association with type 1 diabetes autoimmunity was observed. Antibody frequency in newborns was 0.47%.

CONCLUSIONS:

We demonstrate the value of population-based screening programs for pandemic monitoring.

FUNDING:

The work was supported by funding from the BMBF (FKZ01KX1818).

• Authors: Markus Hippich, Lisa Holthaus, Robin Assfalg, Jose Zapardiel-Gonzalo, Heidi Kapfelsperger, Martin Heigermoser, Florian Haupt, Dominik A Ewald, Tiziana C Welzhofer, Benjamin A Marcus, Susanne Heck, Annika Koelln, Joanna Stock, Franziska Voss, Massimiliano Secchi, Lorenzo Piemonti, Kathrin de la Rosa, Ulrike Protzer, Merle Boehmer, Peter Achenbach, Vito Lampasona, Ezio Bonifacio, Anette-Gabriele Ziegler
• Journal: Med (New York, N.Y.) (Med) Vol. 2 Issue 2 Pg. 149-163.e4 (02 12 2021) ISSN: 2666-6340 [Electronic] United States
• PMID: 33163984 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2020 Elsevier Inc.

Chemical References

• Antibodies, Viral

Topics

• Antibodies, Viral
• COVID-19 (diagnosis)
• Child
• Diabetes Mellitus, Type 1 (diagnosis)
• Humans
• Infant, Newborn
• Public Health
• SARS-CoV-2