Combined Prospective Seroconversion and PCR Data of Selected Cohorts Indicate a High Rate of Subclinical SARS-CoV-2 Infections—an Open Observational Study in Lower Saxony, Germany

• DOI: 10.1128/spectrum.01512-21
• Publication Date: 2022-02-16T15:31:23Z
• Authors: Rebecca Jonczyk; Nils Stanislawski; Lisa K. Seiler; Holger Blume; Stefanie Heiden; Henning Lucas; Samir Sarikouch; Philipp-Cornelius...; Meike Stiesch; Corinna Hauß; Giulietta Saletti; Mariana González-...; Franziska Karola ...; Guus Rimmelzwaan; Albert Osterhaus; Cornelia Blume
• Keywords: Seroconversion; Subclinical infection; Pcr test

Despite lockdown measures, intense symptom-based PCR, and antigen testing, the SARS-CoV-2 pandemic spread further. In this open observational study conducted in Lower Saxony, Germany, voluntary PCR tests were performed from April 2020 until June 2021, supported by serum antibody testing to prove whether subjects with none or few symptoms of COVID-19 is a suitable tool manage pandemic. different mobile stations, 4,817 three working fields participated testing. Serum screening using ViraChip IgG (Viramed, Germany) Elecsys Anti-SARS-CoV-2 assay (Roche, was alongside virus neutralization Subjects questioned regarding comorbidities symptoms. Fifty-one acute infection detected which 31 did not show any possibly characteristic for COVID-19. An additional 37 reported previous (total prevalence 1.82%). Seroconversion discovered 58 known that never had positive test. The latter significantly lower Charlson Comorbidity Index, one third them asymptomatic. 50% all seroconverted subjects, neutralizing antibodies (NAbs) detectable parallel N/S1 (n = 16) N/S1/S2 specific 40) against SARS-CoV-2. NAb titers decreased within 100 days after PCR-confirmed at least 2.5-fold. A relatively high rate subclinical infections may contribute SARS-CoV-2, suggesting addition other intervention strategies, systematic asymptomatic persons enable better control. IMPORTANCE Within study, repeated > 4,700) 1,600) offered fields. identified 51 have test taken externally. Thirty-one display prior addition, without seroconversion. Subjects, undergone having noticed, more often low grade immunization no NAbs, but relevantly contributed Based on these results, we suggest both regular rapid symptomatic individuals, specifically groups workplaces identifiable as close quarter contact, thus increased transference risk, necessary assess therefore reduce virus.