The Impact of Clinical Factors and SARS-CoV-2 Variants on Antibody Production in Vaccinated German Healthcare Professionals Infected Either with the Delta or the Omicron Variant

Abstract

Background: The aim of the rapid introduction of vaccines during the COVID-19 pandemic was a reduction in SARS-CoV-2 transmission and a less frequent occurrence of severe COVID-19 courses. Thus, we evaluated COVID-19 severity in vaccinated individuals to examine variant-specific symptom characteristics and their clinical impact on the serological immune response. Methods: A total of 185 individuals previously vaccinated against and infected with the SARS-CoV-2 Delta (B.1.617.2) or Omicron (BA.4 and BA.5) variant, were enrolled for anti-SARS-CoV-2 anti-N- and anti-RBD/S1-Ig level detection. A structured survey regarding medical history was conducted. Results: In 99.5 percent of cases, outpatient treatment was satisfactory. Specific symptoms associated with variants included ageusia and anosmia in patients with Delta infections and throat pain in Omicron infections. Among Delta-infected individuals with specific symptoms, significantly higher levels of anti-N antibodies were observed. Conclusion: Our study identified variant-specific differences in the amount of SARS-CoV-2 antibody production and COVID-19 symptoms. Despite this, vaccinated individuals with Omicron or Delta infections generally experienced mild disease courses. Additionally, asymptomatic individuals exhibit lower anti-SARS-CoV-2 antibody levels, indicating a clinical correlation between disease-specific antibodies and distinct symptoms, particularly in the case of the Delta variant. In follow-up studies, exploring post-COVID syndrome and focusing on cognitive symptoms in the acute phase of Omicron infections is crucial as it has the potential to longitudinally impact the lives of those affected.

Retrospective Analysis of <em>Clostridioides difficile</em> Infection Rates in Hospitalized Patients during COVID-19 Pandemic. A Unicenter Study in Reus, Spain

“…Conversely, reallocating resources and efforts towards managing COVID-19 and an upsurge in antibiotic consumption for treating pneumonia and respiratory conditions associated with the virus might have produced a contrary effect [6]. The reported findings are inconclusive, with the majority indicating either no impact or a decrease in CDI rates during the initial wave of COVID-19 [10][11][12][13][14][15][16]. Nevertheless, as the pandemic evolved, so too could its impact on CDI incidence.…”

Retrospective Analysis of Clostridioides difficile Infection Rates and Outcomes in Hospitalized Patients during the COVID-19 Pandemic: A Unicenter Study in Reus, Spain

“…Conversely, increased use of antibiotics to treat pneumonia and respiratory conditions associated with the virus may have produced the opposite effect [6,[10][11][12]. The reported findings are inconclusive, with the majority indicating either no impact or a decrease in CDI rates during the initial wave of COVID-19 [13][14][15][16][17][18][19]. Nevertheless, as the pandemic evolved, so too could its impact on CDI incidence.…”