Comparison of the prevalence of SARS-CoV-2 nucleoprotein antibodies in healthcare workers and an unselected adult and paediatric all-comer patient population: insights from a longitudinal study of healthcare workers and concurrent serial cross-sectional studies of patients at an academic medical centre in Austria

Abstract

ObjectivesThis study aimed to estimate and compare the prevalence of the virus-specific antibodies against the SARS-CoV-2 nucleoprotein antigen (anti-SARS-CoV-2 N) in healthcare workers and an all-comer paediatric and adult patient population.Design, setting and participantsA longitudinal study enrolling healthcare professionals and concurrent serial cross-sectional studies of unselected all-comer patients were conducted at an Austrian academic medical centre. Healthcare workers were tested at enrolment and after 1, 2, 3, 6 and 12 months. The cross-sectional studies in patients were conducted at three time periods, which roughly coincided with the times after the first, second and third wave of SARS-CoV-2 in Austria (ie, 24 August–7 September 2020; 8–22 February 2021 and 9–23 November 2021). Anti-SARS-CoV-2 N antibodies were measured using a sandwich electrochemiluminescence assay (Roche).ResultsIn total, 2735 and 9275 samples were measured in 812 healthcare workers (median age: 40 years, 78% female) and 8451 patients (median age: 55 years, 52% female), respectively. Over the entire study period, anti-SARS-CoV-2 N antibodies were detected in 98 of 812 healthcare workers, resulting in a seroprevalence of 12.1% (95% CI 10.0% to 14.5%), which did not differ significantly (p=0.63) from that of the all-comer patient population at the end of the study period (407/3184; 12.8%, 95% CI 11.7% to 14.0%). The seroprevalence between healthcare workers and patients did not differ significantly at any time and was 1.5-fold to 2-fold higher than the number of confirmed cases in Austria throughout the pandemic. In particular, there was no significant difference in the seroprevalence between paediatric and adult patients at any of the tested time periods.ConclusionThroughout the pandemic, healthcare staff and an adult and paediatric all-comer patient population had similar exposure to SARS-CoV-2.Trial registration numberClinicalTrials.gov Identifier:NCT04407429.

Effect of monovalent COVID-19 vaccines on viral interference between SARS-CoV-2 and several DNA viruses in patients with long-COVID syndrome

“…For the first 105 consecutive patients with long-COVID syndrome (age 46 ± 15 years, 36.2% male), clinical data and blood samples were collected from March 15, 2021, to September 30, 2021. Blood samples of age- and sex-matched (46 ± 12 years, 36.2% male) healthy, unvaccinated, non-infected individuals collected from June 18, 2020, to November 11, 2020 (EC: 1387/2020; ClinicalTrials.gov Identifier: NCT04407429) 31 were retrieved from the biobank facility of the Medical University of Vienna (with processing and storage in accordance with the standard operating procedures and an ISO 9001:2015) 32 . Information on sex and age was obtained through the hospital’s electronic database.…”

Interruption of viral interference by anti-SARS-CoV-2 vaccination

“…For the rst 105 consecutive patients with long-COVID syndrome (age 46 ± 15 years, 36.2% male), clinical data and blood samples were collected between March 15th 2021 and September 30th 2021. Blood samples of age-and sex -matched (46 ± 12 years, 36.2% male) healthy individuals, collected during the period between June 18th 2020 and Nov. 11th 2020 (EC: 1387/2020; ClinicalTrials.gov Identi er: NCT04407429) 30 were retrieved from the Biobank facility of the Medical University of Vienna (processing and storage in accordance with the standard operating procedures and an ISO 9001:2015) 31 .…”

Are anti-SARS-CoV-2 S/N IgG/IgM antibodies always predictive of previous SARS-CoV-2 infection?

“…The assessment of anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus disease 2) antibodies is widely used as a surrogate measure of molecular test positivity for identifying previous SARS-CoV-2 infections across many different settings [1]. In particular, the quantification of anti-SARS-CoV-2 antibodies directed against the nucleocapsid protein (N) rather than versus the spike (S) protein of the virus has been employed in many serological surveys in regions where coronavirus disease 2019 (COVID-19) vaccination is conducted with vaccines not containing the sequence (or part of) of the N protein, since the identification of anti-SARS-CoV-2 N antibodies would thus enable to identify the presence of an immune response against the virus and thus, theoretically, to classify the subjects as "infected" or "previously infected" by SARS-CoV-2 [2][3][4].…”