Predictors of SARS-CoV-2 IgG Spike Antibody Responses on Admission and Clinical Outcomes of COVID-19 Disease in Fully Vaccinated Inpatients: The CoVax Study

Abstract

Background: SARS-CoV-2 vaccines have shown high efficacy in protecting against COVID-19, although the determinants of vaccine effectiveness and breakthrough rates are yet to be determined. We aimed at investigating several factors affecting the SARS-CoV-2 IgG Spike (S) antibody responses on admission and clinical outcomes of COVID-19 disease in fully vaccinated, hospitalized patients. Methods: 102 subjects were enrolled in the study. Blood serum samples were collected from each patient upon admission for the semiquantitative determination of the SARS-CoV-2 IgG S levels with lateral flow assays. Factors influencing vaccine responses were documented. Results: 27 subjects had a negative antibody test upon hospital admission. Out of the 102 patients admitted to the hospital, 88 were discharged and 14 died. Both the absence of anti-S SARS-CoV-2 antibodies and poor clinical outcomes of COVID-19 disease were associated with older age, lower Ct values, and a shorter period between symptom onset and hospital admission. Ct values and time between symptom onset and hospitalization were independently associated with SARS-CoV-2 IgG S responses upon admission. The PaO2/FiO2 ratio was identified as an independent predictor of in-hospital mortality. Conclusions: Host- and disease-associated factors can predict SARS-CoV-2 IgG S responses and mortality in hospitalized patients with breakthrough SARS-CoV-2 Infection.

Investigation of admission serum creatinine as a predictor of hospital length of stay in triple-vaccinated COVID-19 inpatients

“…Within the framework of the CoVax study, 3 in this substudy we enrolled 51 hospitalized Greek patients (41 male and 10 female, mean age 79.5±1.6 y) with COVID-19 disease as confirmed by means of real time polymerase chain reaction (RT-PCR). All subjects had received three doses of the Pfizer-BioNTech vaccine.…”

Cutting-Edge Approaches in Respiratory and Critical Care Medicine

“…However, a large study from central Greece after the prevalence of new variants of the virus (Delta and Omicron) demonstrated that vaccination was still effective and provided high protection in terms of mortality and the clinical severity of COVID-19 [ 6 ]. Nevertheless, even in fully vaccinated patients, older age, higher viral load and a shorter period between symptom onset and hospital admission were associated with absence of anti-S SARS-CoV-2 antibodies upon hospital admission and poor clinical outcomes [ 7 ]. On the other hand, individuals vaccinated against COVID-19, but who were still infected by the virus, showed an “excellent boost” in their immune response [ 8 ].…”