Determinants of Pre-Vaccination Antibody Responses to SARS-CoV-2: A Population-Based Longitudinal Study (COVIDENCE UK)

Abstract

Background: Prospective population-based studies investigating multiple determinants of pre-vaccination antibody responses to SARS-CoV-2 are lacking.

Methods: We did a prospective population-based study in SARS-CoV-2 vaccine-naive UK adults between May 1 and Nov 2, 2020. Information on 88 potential risk factors was obtained through online questionnaires, and combined IgG/IgA/IgM responses to SARS-CoV-2 spike glycoprotein were determined in dried blood spots. We used logistic and linear regression to estimate adjusted odds ratios (aORs) and adjusted geometric mean ratios (aGMRs) for potential determinants of SARS-CoV-2 seropositivity (all participants) and antibody titres (seropositive participants only), respectively.

Findings: 1696 (15.2%) of 11,130 participants were seropositive. Factors independently associated with increased risk included frontline health/care occupation (aOR 1.86, 95% CI 1.49–2.33), international travel (1.22, 1.08–1.37), BMI >30 vs <25 kg/m² (1.22, 1.05–1.42), Asian/Asian British vs White ethnicity (1.65, 1.10–2.47), and alcohol consumption ≥15 vs 0 units/week (1.26, 1.06–1.49). Light physical exercise associated with decreased risk (0.80, 0.69–0.93, for ≥10 vs 0–4 h/week). Higher titres associated with frontline health/care occupation (aGMR 1.26, 95% CI 1.13–1.41), international travel (1.10, 1.04–1.16), BMI >30 vs <25 kg/m² (1.09, 1.01–1.17), and Asian/Asian British vs White ethnicity (1.23, 1.03–1.46); these associations were not substantially attenuated by adjustment for disease severity.

Interpretation: Higher alcohol consumption and reduced physical exercise represent new modifiable risk factors for SARS-CoV-2 infection. Recognised associations between Asian/Asian British ethnic origin and obesity and increased risk of SARS-CoV-2 seropositivity were independent of other sociodemographic, clinical, or behavioural factors investigated.

Funding: Barts Charity, Health Data Research UK.

Declaration of Interest: JS declares receipt of payments from Reach plc for news stories written about recruitment to, and findings of, the COVIDENCE UK study. AS is a member of the Scottish Government Chief Medical Officer’s COVID-19 Advisory Group and its Standing Committee on Pandemics. He is also a member of the UK Government’s NERVTAG’s Risk Stratification Subgroup. ARM declares receipt of funding in the last 36 months to support vitamin D research from the following companies who manufacture or sell vitamin D supplements: Pharma Nord Ltd, DSM Nutritional Products Ltd, Thornton & Ross Ltd, Cytoplan Ltd and Hyphens Pharma Ltd. ARM also declares support for attending meetings from the following companies who manufacture or sell vitamin D supplements: Pharma Nord Ltd and Abiogen Pharma Ltd. ARM also declares participation on the Data and Safety Monitoring Board for the Chair, DSMB, VITALITY trial (Vitamin D for Adolescents with HIV to reduce musculoskeletal morbidity and immunopathology). ARM also declares unpaid work as a Programme Committee member for the Vitamin D Workshop. ARM also declares receipt of vitamin D capsules for clinical trial use from Pharma Nord Ltd, Synergy Biologics Ltd and Cytoplan Ltd.

Ethical Approval: COVIDENCE UK was sponsored by Queen Mary University of London and approved by Leicester South Research Ethics Committee (ref 20/EM/0117). It is registered with
ClinicalTrials.gov (NCT04330599).

Keywords: SARS-CoV-2, anti-S IgG IgA IgM, alcohol, physical exercise, ethnicity, obesity, travel, occupation