Associations Of Sars-Cov-2 Serum Igg With Occupation And Demographics Of Military Personnel

BACKGROUND: Countries across the globe have mobilized their armed forces in response to COVID-19, placing them at increased risk for viral exposure. Humoral responses to SARS-CoV-2 among military personnel serve as biomarkers of infection and provide a basis for disease surveillance and recognition of work-related risk factors.METHODS: Enzyme-linked immunosorbent assays (ELISA) were used to measure SARS-CoV-2 spike antigen-specific IgG in serum obtained from N-995 US Army and Air National Guard soldiers between April and June 2020. Occupational information, e.g. military operating specialty (MOS) codes, and demographic data were obtained via questionnaire. Plaque assays with live SARS-CoV-2 were used to assess serum neutralizing capacity for limited subjects (N=12). RESULTS: The SARS-CoV-2 IgG seropositivity rate among the study population was 10.3% and significantly associated with occupation and demographics. Odds ratios were highest for those working in MOS 2T – Transportation (3.6; 95% CI 0.7 – 18) and 92F – Fuel Specialist/Ground and Aircraft (6.8; 95% CI 1.5 – 30), as well as black race (2.2; 95% CI 1.2 – 4.1), household size greater than or equal to 6 (2.5; 95% CI 1.3 – 4.6) and known COVID-19 exposure (2.0; 95% CI 1.2 – 3.3). Seropositivity tracked along major interstate highways and clustered near the international airport and the New York City border. SARS-CoV-2 spike IgG serum exhibited low to moderate SARS-CoV-2 neutralizing capacity with IC50s ranging from 1:15 to 1:280. In limited follow-up testing SARS-CoV-2 serum IgG levels remained elevated up to 7 months. CONCLUSION: The data highlight increased SARS-CoV-2 seroprevalence among National Guard soldiers responding to the COVID-19 pandemic compared to the local civilian population in association with the transportation – related occupations and specific demographics