Factors Influencing Antibody Response to SARS-CoV-2 Vaccination

Area of Science:

• Immunology
• Vaccinology
• Epidemiology

Background:

• The SARS-CoV-2 pandemic highlights the need to understand individual protective antibody levels post-vaccination.
• Data on factors influencing antibody response in healthcare workers (HCWs) are essential for public health strategies.

Purpose of the Study:

• To identify factors affecting anti-receptor binding domain (RBD) IgG antibody levels following SARS-CoV-2 vaccination in HCWs.
• To examine risk factors associated with antibody levels below or above the defined correlation of protection (CoP).

Main Methods:

• A single-center study involving 645 HCWs at Evangelische Kliniken Gelsenkirchen, Germany.
• Participants completed a questionnaire on vaccination history and adverse reactions.
• Anti-RBD IgG antibody levels were measured via blood samples; statistical analysis identified risk factors for antibody levels relative to CoP.

Main Results:

• Age, time since vaccination, and homologous ChAdOx + ChAdOx vaccination regimen were risk factors for antibody levels below CoP.
• Previous COVID-19 infection, number of vaccine doses, and post-vaccination physical complaints were associated with antibody levels above CoP.
• Most participants (94.2%) received two vaccine doses; 12.4% had a prior infection.

Conclusions:

• Antibody response to SARS-CoV-2 vaccination is significantly influenced by age, vaccination regimen, time elapsed since vaccination, and prior infection history.
• These identified risk factors are critical considerations for optimizing future vaccination and booster dose recommendations.
• Understanding these variables can help tailor public health interventions for HCWs and the general population.