Department of Virology, Paul-Ehrlich-Institut, Paul-Ehrlich Street 51-59, 63225, Langen, Germany.
Division of Pharmacovigilance, Paul-Ehrlich-Institut, Paul-Ehrlich Street 51-59, 63325, Langen, Germany.
Sci Rep. 2023 Jul 4;13(1):10820. doi: 10.1038/s41598-023-38077-x.
Escape mutations in the spike protein of SARS-CoV-2 are a major reason for Omicron breakthrough infections. After basal vaccination only very low titers of Omicron neutralizing antibodies are present. However, booster vaccinations induce higher titers against the Omicron variant. The neutralization of the Delta and Omicron variants by sera obtained 6 months after 3rd vaccination and 2 weeks or 6 months after 4th vaccination with a monovalent RNA vaccine (Spikevax) was analyzed. It was observed for the Omicron variant that 6 months after the fourth vaccination, the titer returns to the same very low neutralizing capacity as 6 months after the third vaccination. The Delta variant neutralizing capacity wanes with a comparable kinetic although the titers are higher as compared to the Omicron variant. This indicates that the fourth vaccination with a monovalent vaccine based on the ancestral isolate neither affects the kinetic of the waning nor the breadth of the humoral response.
SARS-CoV-2 刺突蛋白的逃逸突变是奥密克戎突破性感染的主要原因。基础免疫接种后，奥密克戎中和抗体的滴度很低。然而，加强免疫会诱导针对奥密克戎变体的更高滴度。分析了第 3 次接种后 6 个月和第 4 次接种后 2 周或 6 个月时，用单价 RNA 疫苗（Spikevax）获得的血清对德尔塔和奥密克戎变体的中和作用。观察到奥密克戎变体在第 4 次接种后 6 个月，其滴度恢复到与第 3 次接种后 6 个月相同的非常低的中和能力。虽然与奥密克戎变体相比，德尔塔变体的中和能力随时间衰减的动力学更快，但滴度更高。这表明基于原始分离株的单价疫苗的第 4 次接种既不会影响衰减的动力学，也不会影响体液反应的广度。
