Mortality predictors in hospitalised COVID-19 patients and the role of anti-SARS-CoV-2 IgG antibodies and remdesivir.

Background: In a pre-vaccination era serologic tests may be used to evaluate the seroprevalence and efficacy of containment strategies applied to the community. Subsequently, SARS-CoV-2 vaccination has successfully reduced hospitalization and admission to intensive care. The role of antiviral treatment for COVID-19 remains debated.

Objective: We investigated the effect of SARS-CoV-2 IgG Spike (S) antibody responses in hospitalized patients on 30-day mortality. Finally, we assessed whether other predictive factors affected mortality after 30 days.

Methods: Observational study on COVID-19 patients admitted from October 1, 2021, to January 30, 2022.

Results: 520 patients were studied; 108 died at the 30-day follow-up (21%). A borderline significance for mortality was observed in favour of the high antibody titer group (24% vs 17%, p=0.05). From the univariate Cox regression analysis, a high IgG-S titer was significantly correlated to lower 30-day mortality (p=0.04, HR: 0.7; 95%CI: 0.44-0.98). The administration of remdesivir (p=0.01) and the age <65 years (p=2.3e-05) were found to be protective for the considered outcome (respectively, HR: 0.5, 95%CI: 0.34-0.86, and HR: 0.1, 95%CI: 0.04-0.30).

Conclusions: S-antibodies and remdesivir could play a protecting role in increasing the survival of hospitalized COVID-19 patients who are not suffering from a critical disease. Advanced age is a risk factor for poor outcomes among infected people.