Monitoring of SARS-CoV-2 Infection in Ragusa Area: Next Generation Sequencing and Serological Analysis

Area of Science:

• Virology
• Immunology
• Epidemiology

Background:

• The evolution of coronavirus disease 2019 (COVID-19) is linked to new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants.
• Monitoring viral genomics and immune responses is essential for tracking SARS-CoV-2.
• Understanding variant prevalence and immune markers is key in the post-pandemic era.

Purpose of the Study:

• To monitor the trend of SARS-CoV-2 variants in the Ragusa area from January to July 2022.
• To evaluate and compare IgG antibody levels (anti-Nucleocapsid, anti-RBD, anti-S1, anti-S2) between SARS-CoV-2 exposed and unexposed healthcare workers (HCWs).
• To investigate potential correlations between SARS-CoV-2 variants, immune response, and clinical symptoms.

Main Methods:

• Sequencing of 600 samples using next-generation sequencing (NGS) technology.
• Measurement of specific IgG antibody levels in 300 exposed and 300 unexposed HCWs.
• Comparative analysis of SARS-CoV-2 variant trends in Ragusa and Sicily regions.

Main Results:

• BA.1 and BA.2 were the dominant SARS-CoV-2 variants, with BA.3 and BA.4 also detected.
• No direct correlation was found between specific variants and clinical manifestations.
• Higher anti-Nucleocapsid (anti-N) and anti-S2 IgG levels correlated with an increased number of symptoms.
• Natural SARS-CoV-2 infection elicited a stronger antibody response than vaccination.

Conclusions:

• Anti-N IgG evaluation can serve as an early marker for identifying asymptomatic SARS-CoV-2 infections in the post-pandemic period.
• Immune responses, particularly anti-N and anti-S2 levels, are linked to symptom severity.
• The study provides insights into variant circulation and immune markers for COVID-19 surveillance.