# Clinical Significance of Neutralizing Antibodies in COVID-19: Implications for Disease Prognosis

## TL;DR

This study explores how neutralizing antibodies relate to the severity and outcomes of COVID-19, finding that vaccination boosts antibody levels but their presence does not guarantee better recovery.

## Contribution

The study reveals that while vaccination increases neutralizing antibody levels, these levels do not directly correlate with improved clinical outcomes in COVID-19 patients.

## Key findings

- Vaccinated patients had significantly higher total neutralizing antibody levels in both admission and control blood samples.
- The presence of potential neutralizing antibodies in admission blood samples was linked to lower 28-day mortality and milder disease.
- Total neutralizing antibody levels were higher in control samples compared to admission samples.

## Abstract

The pathogenesis of COVID-19 highlights a complex relationship between disease severity and neutralizing antibodies (NAbs). We aimed to investigate the relationships among the total NAb (tNAb) levels, the presence of potential neutralization antibodies (pNAbs), and the clinical outcomes of COVID-19 patients. Patients aged ≥18 years diagnosed between October 2021 and September 2022 were grouped by symptom severity. Blood samples were taken at two time points and data on demographics, epidemiology, and vaccination were recorded. The tNAbs and pNAbs were measured by an enhanced chemiluminescence assay and a surrogate virus neutralization test, respectively. The tNAbs of 68 and the pNAbs of 52 patients were analyzed. Twenty-six (38.2%) patients had severe infection. The 28-day mortality rate was 16.2% (n = 11). The tNAb levels in the control blood samples (CBSs) were significantly higher than those of the admission blood samples (ABSs) (p < 0.001). The statistical analysis showed no relationship between disease severity and pNAbs. Vaccinated patients had significantly higher tNAbs in the ABSs and CBSs (p < 0.001 and p < 0.001, respectively). The presence of pNAbs in the ABSs was correlated with a lower 28-day mortality (p = 0.026) and a milder disease course (p = 0.041). Although these findings support a correlation between tNAbs and disease severity and mortality, their presence seems to be unrelated to favorable clinical outcomes.