The impacts of vaccination status and host factors during early infection on SARS-CoV-2 persistence: a retrospective single-center cohort study

Background: Viral persistence is a crucial factor that influences the transmissibility of SARS-CoV-2. However, the impacts of vaccination and physiological variables on viral persistence have not been adequately clarified.Methods: We collected the clinical records of 377 COVID-19 patients, which contained unvaccinated patients and patients received two doses of an inactivated vaccine or an mRNA vaccine. The impacts of vaccination on disease severity and viral persistence and the correlations between 49 laboratory variables and viral persistence were analyzed separately. Finally, we established a multivariate regression model to predict the persistence of viral RNA.Results: Both inactivated and mRNA vaccines significantly reduced the rate of moderate cases, while the vaccine related shortening of viral RNA persistence was only observed in moderate patients. Correlation analysis showed that 10 significant laboratory variables were shared by the unvaccinated mild patients and mild patients inoc-ulated with an inactivated vaccine, but not by the mild patients inoculated with an mRNA vaccine. A multi-variate regression model established based on the variables correlating with viral persistence in unvaccinated mild patients could predict the persistence of viral RNA for all patients except three moderate patients inoculated with an mRNA vaccine.Conclusion: Vaccination contributed limitedly to the clearance of viral RNA in COVID-19 patients. While, labo-ratory variables in early infection could predict the persistence of viral RNA.