Publication:

Post-vaccination SARS-CoV-2 IgG spike antibody responses and risk factors among healthcare workers: a cross-sectional serological study

Background Healthcare workers (HCWs) are considered at high risk of SARS-CoV-2 infection due to direct exposure to patients. Vaccination has been recommended as the main protective strategy against SARS-CoV-2 severity and even death among HCWs and the geriatric population.

Methods In the current cross-sectional serological study, demographic details, risk factors and blood samples were collected from 1044 HCWs working at Government Medical College and its associated hospitals (GMC&AHJ), Jammu (J&K). Levels of SARS-CoV-2 spike antibody levels assay were determined after six months of the 2nd dose of the COVISHIELD vaccine using the chemiluminescent microparticle immunoassay method (CMIA).

Results SARS-CoV-2 IgG spike antibodies were detected in 97.4% of HCWs. SARS-CoV-2 IgG spike seropositivity was found to be higher among females than males. SARS-CoV-2 IgG spike antibody levels were found to be statistically significantly higher in age group 1 (18–30 years) compared to age group 2 (18–50 years) and age group 3 (50 years and above) (both p<0.01) in males and females. IgG spike antibody titers were found significantly higher in those who were SARS-CoV-2 positive before vaccination than those who were not, whereas the presence of comorbidity, high BMI and smoking has adversely lowered the SARS-CoV-2 IgG spike antibody titer in the present study.

Conclusions It was observed that SARS-CoV-2 IgG spike seropositivity remained in almost all participants even after six months of vaccination. However, it was observed that risk factors such as smoking, High BMI, and comorbidity have detrimental effects on IgG spike antibody titer.