POPULATION-BASED SERO-EPIDEMIOLOGICAL STUDY PROTOCOL FOR THE IMPACT OF SMOKING ON SARS-COV-2 INFECTION AND COVID-19 OUTCOMES - THE TROINA STUDY

After the global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), research has highlighted several aspects of the pandemic, focusing on clinical features and risk factors associated with infection and disease severity. However, emerging results on the role of smoking in SARS-CoV-2 infection susceptibility or COVID-19 outcomes are conflicting, and their robustness remains uncertain. In this context, this project aims at quantifying the proportion of SARS-CoV-S antibody seroprevalence, studying the changes in antibody levels over time, and analyzing the association between smoking status and infection using seroprevalence data. The added value of this research is that the current smoking status of the population to be studied will be biochemically verified, in order to avoid the bias associated with self-reported smoking status. As such, the results from this survey may provide actionable metric to study the role of smoking in SARS-CoV-2 spread, and therefore implement the most appropriate public health measures to control the pandemic. The research design involves a 6-month prospective cohort study with serial sampling of the same individuals. Each participant will be surveyed about their demographics and COVID-19-related information, and blood sampling will be collected upon recruitment and at specified follow-up time points (namely, after 8 and 24 weeks). Blood samples will be screened for the presence of SARS-CoV-2 specific antibodies and serum cotinine. Overall, we expect to find a higher prevalence of antibodies in individuals at high-risk for viral exposure (i.e., healthcare or other essential workers), according to previous literature, and to refine current estimates on the association between smoking status and SARS-CoV-2/COVID-19. Our results may serve as a reference for future clinical research and the methodology could be exploited in public health sectors and policies.