Abstract
Although immune response enhancement has been reported after primary and booster vaccines of CoronaVac, neutralization breadth of SARS-CoV-2 variants is still unclear. In the present study, we examined the neutralization magnitude and breadth of SARS-CoV-2 variants including Beta (B.1.351), Delta (B.1.617.2) and Omicron (B.1.1.529) in 33 convalescent COVID-19 patients and a cohort of 55 medical staff receiving primary CoronaVac vaccines and an additional homologous booster dose. Results showed that, as compared with the two-dose primary vaccination, the homologous booster dose achieved 2.24-, 3.98-, 4.58- and 2.90-fold increase in neutralization titer against wild-type, Beta, Delta, and Omicron, respectively. After booster dose, neutralization titer reduction for variants was less than that after the primary vaccine or that for convalescents. The proportion of recipients able to neutralize 2 or more variants increased from 36.36% post the primary vaccination to 87.27% after the booster. Significant increase in neutralization breadth of 1.24 (95% confidence interval (CI), 0.89-1.59) variants was associated with a log 10 increase in neutralization titer against the wild-type. In addition, anti-RBD IgG level was identified as an excellent surrogate for positive neutralization of SARS-CoV-2 and neutralization breadth of variants. These findings highlight the value of an additional homologous CoronaVac dose in broadening the cross-neutralization against SARS-CoV-2 variants, and are critical for informing the booster dose vaccination efforts.
Keywords: Omicron; SARS-CoV-2; booster vaccination; neutralization breadth; variants.
【저자키워드】 SARS-CoV-2, omicron, variants., booster vaccination, neutralization breadth, 【초록키워드】 Vaccine, immune response, vaccination, B.1.351, neutralization, variant, SARS-CoV-2 variant, CoronaVac, Delta, B.1.617.2, variants, Cohort, SARS-CoV-2 variants, cross-neutralization, Beta, B.1.1.529, homologous, Critical, booster dose, booster, breadth, Booster vaccine, dose, Anti-RBD IgG, reduction, 95% confidence interval, wild-type, positive, neutralization titer, recipient, neutralize, highlight, log, Result, examined, proportion, reported, addition, receiving, less, magnitude, increase in, Significant, convalescent COVID-19 patient, 【제목키워드】 CoronaVac, magnitude, the antibody response, SARS-CoV-2 virus,