Serological reactivity of inactivated SARS-CoV-2 vaccine based on an S-RBD neutralizing antibody assay

Abstract

Objectives This study aimed to explore the regularity of S-RBD domain antibody reactivity after immunization with inactivated SARS-CoV-2 vaccine and evaluate the immune response effect of this vaccine. Design or methods Venous blood samples were collected from 1156 healthcare workers who participated in the phase III clinical trial of SARS-CoV-2 inactivated vaccine. The S-RBD domain antibody levels in serum were detected by ELISA 14 days after the first and second active immunization respectively. Results The positive rate of S-RBD domain antibody against SARS-CoV-2 was 28.03% and 86.76% respectively after inoculation of the first and second vaccination. The mean inhibition rate of S-RBD domain antibody against positive samples was (57.18 ± 18.87) % after the second vaccination at 14 days. Gender and age had no effects on the positive rate. The positive rate was decreased in the high BMI group. Single-factor logistic analysis showed that there was no significant correlation between age and positive rate. BMI was negatively correlated with the positive rate. Conclusions After two times of immunization, the positive rate of SARS-CoV-2 S-RBD domain antibody was high, and the vaccine had good immunogenicity. The improvement of the immune strategy should focus on the effects of BMI and other factors.

Antibody responses to COVID‐19 vaccination in people with obesity: A systematic review and meta‐analysis

“…After title and abstract screening, we retrieved 193 full‐text reports for further review. Finally, 11 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 articles met our inclusion criteria. All included studies were of high quality (NOS > 6).…”

Immune Response to CoronaVac and Its Safety in Patients with Type 2 Diabetes Compared with Healthcare Workers

“…The study reported that the S-RBD-neutralizing antibody was significantly lower in the BMI >25.00 kg/m 2 group compared to the 21.00–25.00 kg/m 2 group ( p <0.05). Additionally, the S-RBD-neutralizing antibody in both the 21.00–25.00 kg/m 2 and >25.00 kg/m 2 groups was significantly lower than that of the ≤21.00 kg/m 2 group ( p <0.05) [ 36 ]. In our study, the healthcare workers had a median body weight of 65.25 (55–73.5) kg and a median BMI of 23.61 (21.51, 26.24) kg/m 2 , which is considered overweight in the Asian population.…”

Characterizing the cellular and molecular variabilities of peripheral immune cells in healthy recipients of BBIBP-CorV inactivated SARS-CoV-2 vaccine by single-cell RNA sequencing

“…The intensity of the colour was measured at 450 nm using a MultiSkan FC reader (51119000, Thermo Fisher Scientific Inc., Waltham, MA, USA). The anti-SARS-Cov-2 RBD neutralizing antibody were detected using SARS-CoV-2 Neutralizing Antibodies Test Kit (DD3101, Vazyme Biotech, Nanjing China) according to the manufacturer’s protocol as previously reported [ 24 ], which is based on the competition between the neutralizing antibodies in serum and ACE2 to horseradish peroxidase-labelled RBD protein. The optical density (OD) was measured at 450 nm using a MultiSkan FC reader.…”

“…The optical density (OD) was measured at 450 nm using a MultiSkan FC reader. The signal inhibition rate (SIR) was calculated with the equation SIR = (1-OD of sample/mean OD of negative control) × 100% [ 24 ]. The serum levels of IFN-γ, IFN-α, interleukin (IL)−1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-17A and tumour necrosis factor (TNF)-α were measured using an Aimplex kit (P010041, CEGER, Hangzhou, China) and flow cytometry (BD FortessaX20), following the manufacturer’s instructions.…”