PLoS ONE (Jan 2022)

SARS-CoV-2 antibody persistence after five and twelve months: A cohort study from South-Eastern Norway.

  • Marjut Sarjomaa,
  • Lien My Diep,
  • Chi Zhang,
  • Yngvar Tveten,
  • Harald Reiso,
  • Carina Thilesen,
  • Svein Arne Nordbø,
  • Kristine Karlsrud Berg,
  • Ingeborg Aaberge,
  • Neil Pearce,
  • Hege Kersten,
  • Jan Paul Vandenbroucke,
  • Randi Eikeland,
  • Anne Kristin Møller Fell

DOI
https://doi.org/10.1371/journal.pone.0264667
Journal volume & issue
Vol. 17, no. 8
p. e0264667

Abstract

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ObjectivesTo assess total antibody levels against Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS CoV-2) spike protein up to 12 months after Coronavirus Disease (COVID-19) infection in non-vaccinated individuals and the possible predictors of antibody persistence.MethodsThis is the first part of a prospective multi-centre cohort study.ParticipantsThe study included SARS-CoV-2 real-time polymerase chain reaction (RT-PCR) positive and negative participants in South-Eastern Norway from February to December 2020. Possible predictors of SARS-CoV-2 total antibody persistence was assessed. The SARS-CoV-2 total antibody levels against spike protein were measured three to five months after PCR in 391 PCR-positive and 703 PCR-negative participants; 212 PCR-positive participants were included in follow-up measurements at 10 to 12 months. The participants completed a questionnaire including information about symptoms, comorbidities, allergies, body mass index (BMI), and hospitalisation.Primary outcomeThe SARS-CoV-2 total antibody levels against spike protein three to five and 10 to 12 months after PCR positive tests.ResultsSARS-CoV-2 total antibodies against spike protein were present in 366 (94%) non-vaccinated PCR-positive participants after three to five months, compared with nine (1%) PCR-negative participants. After 10 to 12 months, antibodies were present in 204 (96%) non-vaccinated PCR-positive participants. Of the PCR-positive participants, 369 (94%) were not hospitalised. The mean age of the PCR-positive participants was 48 years (SD 15, range 20-85) and 50% of them were male. BMI ≥ 25 kg/m2 was positively associated with decreased antibody levels (OR 2.34, 95% CI 1.06 to 5.42). Participants with higher age and self-reported initial fever with chills or sweating were less likely to have decreased antibody levels (age: OR 0.97, 95% CI 0.94 to 0.99; fever: OR 0.33, 95% CI 0.13 to 0.75).ConclusionOur results indicate that the level of SARS-CoV-2 total antibodies against spike protein persists for the vast majority of non-vaccinated PCR-positive persons at least 10 to 12 months after mild COVID-19.