Comparison of the Clinical and Laboratory Findings and Outcomes of Hospitalized COVID-19 Patients Who Were Either Fully Vaccinated with Coronavac or Not: An Analytical, Cross Sectional Study

Abstract

COVID-19 vaccines are highly protective against severe disease; however, vaccine breakthrough infections resulting in hospitalization may still occur in a small percentage of vaccinated individuals. We investigated whether the clinical and microbiological features and outcomes were different between hospitalized COVID-19 patients who were either fully vaccinated with Coronovac or not. All hospitalized COVID-19 patients who had at least one dose of Coronavac were included in the study. The oldest unvaccinated patients with comorbidities, who were hospitalized during the same period, were chosen as controls. All epidemiologic, clinical and laboratory data of the patients were recorded and compared between the fully vaccinated and unvaccinated individuals. There were 69 and 217 patients who had been either fully vaccinated with Coronavac or not, respectively. All breakthrough infections occurred in the first 3 months of vaccination. Fully vaccinated patients were older and had more comorbidities than unvaccinated patients. There were minor differences between the groups in symptoms, physical and laboratory findings, anti-spike IgG positivity rate and level, the severity of COVID-19, complications, and clinical improvement rate. The mortality rate of fully vaccinated patients was higher than the mortality rate in unvaccinated patients in univariate analysis, which was attributed to the fact that vaccinated patients were older and had more comorbidities. The severity and clinical outcomes of hospitalized patients with breakthrough COVID-19 after Coronavac vaccination were similar to those of unvaccinated patients. Our findings suggest that the immune response elicited by Coronovac could be insufficient to prevent COVID-19-related severe disease and death within 3 months of vaccination among elderly people with comorbidities.

Effect of vaccination status on CORADS and computed tomography severity score in hospitalized COVID-19 patients: A retrospective study

“…In the study of Mahajan et al [ 16 ], where they evaluated vaccinated and unvaccinated patients with a positive SARS-CoV-2 PCR test, they found that the CT-SS of vaccinated people was mild-moderate, while unvaccinated individuals were moderate-severe. Again, in the studies conducted by Russo et al [ 4 ], Ravindra et al [ 5 ], Fatima et al [ 6 ], and Yavuz et al [ 17 ], when the CT SS of vaccinated and unvaccinated patients were compared, it was shown that vaccinated patients had milder pulmonary involvement. In our study, it was shown that unvaccinated individuals had moderate-severe lung involvement, and patients who received two doses of CoronaVac or two doses of BioNTech or three doses of vaccine had moderate lung involvement.…”

“…In a study evaluating the effectiveness of the CoronaVac vaccine and hospitalizing 292 patients diagnosed with COVID-19, no significant difference was found between the acute phase reactants of vaccinated and unvaccinated patients[ 17 ]. In another study conducted in Poland, no significant difference was found between acute phase reactants[ 18 ].…”

Comparison of Clinical Outcomes of Coronavac Vaccinated and Unvaccinated Older Adults With Hospitalized Covid-19

“…Many studies have revealed that COVID-19 patients with underlying diseases have increased risk of poor prognosis (15)(16)(17)(18). In the study of Yavuz et al, chronic pulmonary disease, malignancy, chronic kidney disease, and cardiovascular diseases were reported as independent risk factors for mortality (17).…”

“…Many studies have revealed that COVID-19 patients with underlying diseases have increased risk of poor prognosis (15)(16)(17)(18). In the study of Yavuz et al, chronic pulmonary disease, malignancy, chronic kidney disease, and cardiovascular diseases were reported as independent risk factors for mortality (17). In the study by of Sezen et al, mortality was found to be significantly higher in patients with CCI ≥ 1 (18); however, there is a limited number of studies evaluating the effect of comorbid diseases on prognosis in patients with CoronaVac.…”

Short-Term Effect of SARS-CoV-2 Spike Protein Receptor-Binding Domain-Specific Antibody Induction on Neutrophil-Mediated Immune Response in Mice

“…Neutrophils can mediate the vaccination- and specific antibody-associated side effects such as thrombosis [ 15 ]. At the same time, vaccination and RBD-specific antibodies prevent the COVID-19-associated severe inflammation and complications, some of which are mediated by neutrophils [ 16 ]. Thus, the effects of SARS-CoV-2 antigen-specific antibody induction on neutrophils are an important but poorly investigated.…”