Measurements of Anti-SARS-CoV-2 Antibody Levels after Vaccination Using a SH-SAW Biosensor

Area of Science:

• Biomedical Engineering
• Immunology
• Infectious Diseases

Background:

• Vaccination is crucial for controlling the COVID-19 pandemic.
• Vaccines can cause adverse effects, particularly in individuals with chronic conditions.
• Monitoring antibody levels is important to guide vaccination strategies and prevent unnecessary procedures.

Purpose of the Study:

• To develop and validate a rapid biosensor for quantifying anti-SARS-CoV-2 S protein antibodies.
• To assess the kinetics of antibody response following COVID-19 vaccination.
• To compare antibody levels induced by different vaccine types (mRNA vs. adenovirus).

Main Methods:

• Development of a novel Surface Acoustic Wave (SAW) biosensor coated with SARS-CoV-2 spike protein.
• Quantification of anti-SARS-CoV-2 S protein antibodies using 5 μL of finger blood.
• Determination of the biosensor's Limit of Detection (LoD) and cut-off point.
• Analysis of antibody concentration changes at different time points post-vaccination.

Main Results:

• The SH-SAW biosensor provides rapid (40 s) antibody quantification.
• Antibody concentrations peaked 10-14 days after the first dose and 7-9 days after the second dose.
• mRNA vaccines (Moderna, BNT) induced higher antibody levels than the adenovirus vaccine (AZ).
• The biosensor demonstrated high accuracy with a Youden’s J statistic of 0.94733.

Conclusions:

• SH-SAW biosensor technology offers a simple and effective method for in vitro diagnostics.
• This technology can aid in monitoring local COVID-19 prevalence and vaccine immunogenicity.
• The findings support personalized vaccination strategies based on individual antibody responses.