Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jun;293(6):763-781.
doi: 10.1111/joim.13637. Epub 2023 Apr 17.

SARS-CoV-2 antibody dynamics over time and risk factors associated with infection and long COVID-19 symptoms in large working environments

Cecilie Bo Hansen  1 , Kristina Dvoncova  1 , Laura Pérez-Alós  1 , Kamille Fogh  2 , Johannes Roth Madsen  1 , Caroline Hartwell Garred  1 , Ida Jarlhelt  1 , Pernille Brok Nielsen  2 , Steffan Svejgaard Petersen  3 , Charlotte Gandsø Fjordager  3 , Klara Tølbøll Lauritsen  3 , Linda Hilsted  4 , Lasse Boding  5 , Kasper Karmark Iversen  2   6 , Liselotte Hyveled  7 , Peter Garred  1   6
Affiliations
Free article

SARS-CoV-2 antibody dynamics over time and risk factors associated with infection and long COVID-19 symptoms in large working environments

Cecilie Bo Hansen et al. J Intern Med. 2023 Jun.
Free article

Abstract

Background: Factors influencing SARS-CoV-2 antibody dynamics, transmission, waning and long COVID-19 symptomatology are still not fully understood.

Methods: In the Danish section of the Novo Nordisk Group, we performed a prospective seroepidemiological study during the first and second waves of the COVID-19 pandemic. All employees and their household members (>18 years) were invited to participate in a baseline (June-August 2020), 6-month follow-up (December 2020-January 2021), and 12-month follow-up (August 2021) sampling. In total, 18,614 accepted and provided at least one blood sample and completed a questionnaire regarding socioeconomic background, health status, previous SARS-CoV-2 infection, and persistent symptoms. Total antibody and specific IgM, IgG and IgA levels against recombinant receptor binding domain were tested.

Results: At baseline, the SARS-CoV-2-antibody seroprevalence was 3.9%. At 6-month follow-up, the seroprevalence was 9.1%, while at 12-month follow-up, the seroprevalence was 94.4% (after the vaccine roll-out). Male sex and younger age (18-40 years) were significant risk factors for seropositivity. From baseline to the 6-month sampling, we observed a substantial waning of IgM, IgG and IgA levels (p < 0.001), regardless of age, sex and initial antibody level. An increased antibody level was found in individuals infected prior to vaccination compared to vaccinated infection naïves (p < 0.0001). Approximately a third of the seropositive individuals reported one or more persistent COVID-19 symptoms, with anosmia and/or ageusia (17.5%) and fatigue (15.3%) being the most prevalent.

Conclusion: The study provides a comprehensive insight into SARS-CoV-2 antibody seroprevalence following infection and vaccination, waning, persistent COVID-19 symptomatology and risk factors for seropositivity in large working environments.

Keywords: SARS-CoV-2; antibody; infection; long COVID; transmission; waning; working environment.

PubMed Disclaimer

References

    1. WHO. Coronavirus disease 2019 (COVID-19) situation report-51. 2020. Available from: https://www.who.int/docs/default-source/coronaviruse/situation-reports/2....
    1. WHO. 2020. Who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19-11-march-2020. Available from: https://www.who.int/director-general/speeches/detail/.
    1. The Danish Health Authority. Current data on the development of coronavirus. 2021. Available from: https://www.sst.dk/en/English/Corona-eng/Status-of-the-epidemic/COVID-19....
    1. Danske Regioner. The Danish COVID-19 vaccination programme. Available from: https://www.regioner.dk/sundhed/coronaviruscovid-19/vaccination-mod-covi....
    1. Iversen K, Bundgaard H, Hasselbalch RB, Kristensen JH, Nielsen PB, Pries-Heje M, et al. Risk of COVID-19 in healthcare workers in Denmark: an observational cohort study. Lancet Infect Dis. 2020;20(12):1401-8.

Publication types

LinkOut - more resources