New studies show the importance of large-scale SARS-CoV-2 antibody screening

A new study led by Helmholtz Zentrum München shows that SARS-CoV-2 exposure in children in Bavaria, Germany, is six times higher than reported cases. This highlights the value of population-based antibody screening for pandemic monitoring. The study also describes a new approach for accurate measurement of antibodies to SARS-CoV-2.

A new approach for measuring antibodies to SARS-CoV-2

Current antibody testing strategies are known for their non-specificity and account for the majority of false positive results. A German researcher led by Professor Anette-G. Helmholtz Zentrum München’s Ziegler has developed a new approach to measuring antibodies to SARS-CoV-2 by defining antibody positivity as a double-positive response to both the viral receptor-binding domain and the nucleocapsid protein. This two-step approach provides more accurate test results with near 100% specificity and over 95% sensitivity.

Ziegler and her group are already conducting a large screening study of presymptomatic type 1 diabetes mellitus “Fr1da” in children, so this new testing approach for SARS-CoV-2 antibody is easy and rapid to existing studies. Can be applied to. infrastructure.

Results of SARS-CoV-2 antibody screening

Between January 2020 and July 2020, researchers found that approximately 12,000 children aged 1 to 18 years in Bavarian were positive for SARS-CoV-2 double antibody (participants in the Fr1da study). ) Blood sample was tested. They detected an average antibody frequency of 0.87% from April to July. The frequency of these antibodies was 6-fold higher than the incidence of virus-positive cases reported by the Bavarian Department of Health and Food Safety (Bavarian children aged 0-18 years from April to July).

The results did not show differences in gender or age. Almost half (47%) of antibody-positive children were asymptomatic. In children with virus-positive families, one-third (35%) had antibodies. This shows that the expected prevalence of infection in children is higher than in most previous studies. Regional results within Bavaria revealed substantial geographical differences with the highest antibody frequencies (“hot spots”) in southern Bavaria.

The children in this study were also tested for type 1 diabetes autoantibodies, which are early markers of presymptomatic type 1 diabetes. Researchers did not see an increase in the frequency of these autoantibodies. This suggests that childhood COVID-19 is not associated with type 1 diabetes.

Impact on COVID-19 measures

“Our study has yielded important results that reveal a discrepancy between reported virus-positive cases and antibody prevalence,” he conducted as lead author and postdoc at Helmholtz Zentrum München. Markus Hippich said. “Many people, almost half of their children, do not show symptoms of COVID-19 and are therefore not tested, so virus testing alone is not a sufficient approach. Reliable data About actual virus exposure “

“A national antibody screening program with high specificity and sensitivity provides the country with reliable data to prepare for the future, contains virus spread, and regions and countries,” said Ziegler, who leads Professor Annette-G’s research. It may help monitor the impact of containment policies. “

Dashboard

Research results, including information on the geographical spread of antibody frequencies, Research dashboard.. The numbers are updated monthly.

Limitations

Antibodies to SARS-CoV-2 can take 1 to 4 weeks to express. Therefore, these measurements cannot be used for modern prevalence screening. Currently, there is no evidence of SARS-CoV-2. antibody It leads to immunity. If this is shown to be the case, the results of this screening may provide relevant information about the immune status of. Children In Bavarian.