Longitudinal Study on Seroprevalence and Immune Response to SARS-CoV-2 in a Population of Food and Retail Workers Through Transformation of ELISA Datasets

Since the onset of the global pandemic caused by the emergence and spread of SARS-CoV-2 in early 2020, numerous studies have been conducted worldwide to understand our immune response to the virus. This study investigates the humoral response elicited by vaccination and by SARS-CoV-2 infection in the poorly studied food and retail workers in the Quebec City area. The 1.5-year study period spans from early 2021, when vaccination became available in this region, to mid-2022, following waves of virulence due to the emergence of the first Omicron variants. Cross-correlated with data on workplace protective measures, pre-existing conditions, activities and other potentially relevant factors, this longitudinal study applies recently developed ELISA data transformation to our dataset to obtain normal distribution. This unlocked the possibility to use the ANOVA-Welsh method for statistical analysis to obtain a statistical perspective of the serological response. Our work allows the identification of factors contributing to statistically relevant differences in the humoral response of the cohort and strengthens the utility of the use of decentralized approaches to serological analysis.