Antibody response to inactivated COVID-19 vaccine (CoronaVac) in immune-mediated diseases: a controlled study among hospital workers and elderly

Abstract

Objective To assess antibody response to inactivated COVID-19 vaccine in patients with immune-mediated diseases (IMD) among hospital workers and people aged 65 and older. Methods In this cross-sectional study, we studied 82 hospital workers with IMD (mean age: 42.2 +/- 10.0 years) and 300 (mean age: 41.7 +/- 9.9 years) controls. Among + 65 aged population, we studied 22 (mean age: 71.4 +/- 4.5 years) patients and 47 controls (mean age: 70.9 +/- 4.8 years). All study subjects had a negative history for COVID-19. Sera were obtained after at least 21 days following the second vaccination. Anti-spike IgG antibody titers were measured quantitatively using a commercially available immunoassay method. Results Patients with IMD were significantly less likely to have detectable antibodies than healthy controls both among the hospital workers (92.7% vs 99.7%, p = 60 years both in patient and control populations. Whether these individuals should get a booster dose warrants further studies.