Skip to main content
Top
Published in:

Open Access 01-12-2025 | Polymerase Chain Reaction | Research

SARS-CoV-2-specific humoral immunity in a Norwegian cohort between 2020 and 2023

Authors: Marjut Sarjomaa, Kristine Karlsrud Berg, Keson Jaioun, Yngvar Tveten, Hege Kersten, Harald Reiso, Randi Eikeland, Carina Thilesen, Svein Arne Nordbø, Ingeborg S. Aaberge, Neil Pearce, Anne Kristin Moeller Fell

Published in: BMC Medicine | Issue 1/2025

Login to get access

Abstract

Background

We have previously reported on natural humoral immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a Norwegian cohort between 2020 and 2021. In this study, we evaluated long-term humoral (including vaccination-induced) immunity in the same cohort and assessed predictors of high antibody levels against spike protein, as well as the persistence of antibodies against the virus spike and nucleocapsid proteins.

Methods

Vaccination data and antibody levels against the spike and nucleocapsid proteins were collected at 12 (only in infected participants) and 24 months (in both infected and uninfected participants) after the participants’ first polymerase chain reaction (PCR) tests for the virus. Antibody levels against spike protein at 24 months were categorized as high or low based on the 50th percentile. Possible predictors of high antibody levels against spike protein were examined using univariate and multivariate logistic regression models.

Results

Of 1119 original participants (400 PCR + and 719 PCR −), 574 responded to our questionnaires and were invited to antibody measurements (median age: 51 years; women: 59%). Vaccination data showed that 11% were fully immunized, and 85% were booster-immunized at 24 months. Antibody levels were evaluated in 72% (287/400) of the PCR + participants at 12 months and 58% (233/400) at 24 months. At 12 and 24 months, we observed that 97% (278/287) and 100% (233/233), respectively, still had antibodies against the spike protein, and 86% (248/287) and 95% (221/233), respectively, against the nucleocapsid protein. Antibody levels were also evaluated in 34% (247/719) of those in the PCR − group, which revealed that 99.5% and 69% had detectable antibodies against spike and nucleocapsid proteins, respectively, at 24 months. Irrespective of pre-vaccination SARS-CoV-2 infection status, the booster-immunized participants were 3.7 × more likely to have high antibody levels against spike protein vs the non-booster-immunized ones. Those aged > 60 years had the highest median antibody levels against the spike protein and were more likely to be booster-immunized.

Conclusions

Our findings highlight the benefits of booster vaccinations for humoral immune responses. Long-term antibody levels against the SARS-CoV-2 spike protein were higher in booster-immunized participants vs the non-booster-immunized, irrespective of pre-vaccination infection status.
Trial registration.
146,469: The COVID-19 study in Telemark and Agder—COVITA. ClinicalTrials.gov ID: NCT04514003.
Appendix
This content is only visible if you are logged in and have the appropriate permissions.
Literature
This content is only visible if you are logged in and have the appropriate permissions.
Metadata
Title
SARS-CoV-2-specific humoral immunity in a Norwegian cohort between 2020 and 2023
Authors
Marjut Sarjomaa
Kristine Karlsrud Berg
Keson Jaioun
Yngvar Tveten
Hege Kersten
Harald Reiso
Randi Eikeland
Carina Thilesen
Svein Arne Nordbø
Ingeborg S. Aaberge
Neil Pearce
Anne Kristin Moeller Fell
Publication date
01-12-2025
Publisher
BioMed Central
Published in
BMC Medicine / Issue 1/2025
Electronic ISSN: 1741-7015
DOI
https://doi.org/10.1186/s12916-025-04171-2

Keynote webinar | Spotlight on innovations in retinal disease

  • Webinar | 08-07-2025 | 18:00 (CEST)

On-demand video coming soon

Retinal diseases are a significant cause of vision impairment and blindness worldwide, but the diagnostic and treatment landscape is rapidly evolving. Explore groundbreaking advances in retinal imaging and gene therapy, before taking a deep dive into emerging treatments for wet AMD.

Prof. Giuseppe Querques
Prof. Dr.med. Katarina Stingl
Dr. Miklos Schneider
Developed by: Springer Medicine
Notify me
Webinar

How can your team use biomarkers to improve management of AD? (Link opens in a new window)

Our experts explore using biomarker tests and interpreting results, establishing a shared decision-making approach with patients and caregivers, and applying biomarker testing to guide treatment strategies.

This content is intended for healthcare professionals outside of the UK.

Supported by:
  • Lilly
Developed by: Springer Health+ IME
Register your interest