COVID-19 exposure risks and protective measures in East Londons healthcare and academic sectors: Insights and applications of GloBody technology for infectious disease monitoring

The COVID-19 pandemic highlighted the need for effective protection and rapid development of tests to track and quantify seroconversion through natural infection and vaccination. Recombinant proteins, consisting of the SARS-CoV-2 nucleocapsid and Spike Receptor Binding Domains (RBD) fused with nanoluciferase reporters (GloBodies) were designed and produced. The SARS-CoV-2 specific antibody within serum, from venous blood or eluted from local or remotely-obtained dried blood spots, form a complex with the GloBody, which can be captured on immobilized Protein G or anti-isotype antibody with the retained nanoluciferase activity being proportional to specific antibody levels. Natural infection, vaccination and human and animal SARS-CoV-2 specific antibodies were detectable. These were used to serially monitor infection and vaccination responses in dental healthcare workers (n=82), medical healthcare workers (n=72) and laboratory-based scientists (n=62) within the Royal London, dental and medical hospitals and associated university research institute in Whitechapel, East London. This indicated temporally distinct infection and vaccination profiles, consistent with hospital deployments and local and national lockdowns by dentists and scientists. As such, medical healthcare workers had twice the odds of experiencing COVID-19 symptoms (2.01 95%CI 1.13- 3.58. P<0.001) compared to dentists, who were more at risk than scientists. Likewise, those who performed virus exposure-prone procedures exhibited twice (1.98. 95% CI 1.18-3.34 P=0.01) the odds of symptoms and exhibited higher nucleocapsid titres (0.21 95%CI 0.05-0.38. P=0.012), indicative of higher infection levels. As predicted vaccination was associated with reduced infection risk as shown by reduced titre of nucleocapsid titres (-0.21 95% CI -0.34- - 0.17. P<0.001 and elevated Log10 RBD GloBody titres (1.18. 95%CI 1.09-1.26. P<0.001). The GloBody technology proved to be a versatile and scalable platform for rapid deployment.