The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China.
Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, National Clinical Research Center for Infectious Diseases, Beijing 100039, China.
Viruses. 2023 Apr 4;15(4):917. doi: 10.3390/v15040917.
Humoral immunity confers protection against COVID-19. The longevity of antibody responses after receiving an inactivated vaccine in individuals with previous SARS-CoV-2 infection is unclear. Plasma samples were collected from 58 individuals with previous SARS-CoV-2 infection and 25 healthy donors (HDs) who had been vaccinated with an inactivated vaccine. The neutralizing antibodies (NAbs) and S1 domain-specific antibodies against the SARS-CoV-2 wild-type and Omicron strains and nucleoside protein (NP)-specific antibodies were measured using a chemiluminescent immunoassay. Statistical analysis was performed using clinical variables and antibodies at different timepoints after SARS-CoV-2 vaccination. NAbs targeting the wild-type or Omicron strain were detected in individuals with previous SARS-CoV-2 infection at 12 months after infection (wild-type: 81%, geometric mean (GM): 20.3 AU/mL; Omicron: 44%, GM: 9.4 AU/mL), and vaccination provided further enhancement of these antibody levels (wild-type: 98%, GM: 53.3 AU/mL; Omicron: 75%, GM: 27.8 AU/mL, at 3 months after vaccination), which were significantly higher than those in HDs receiving a third dose of inactivated vaccine (wild-type: 85%, GM: 33.6 AU/mL; Omicron: 45%, GM: 11.5 AU/mL). The level of NAbs in individuals with previous infection plateaued 6 months after vaccination, but the NAb levels in HDs declined continuously. NAb levels in individuals with previous infection at 3 months post-vaccination were strongly correlated with those at 6 months post-vaccination, and weakly correlated with those before vaccination. NAb levels declined substantially in most individuals, and the rate of antibody decay was negatively correlated with the neutrophil-to-lymphocyte ratio in the blood at discharge. These results suggest that the inactivated vaccine induced robust and durable NAb responses in individuals with previous infection up to 9 months after vaccination.
体液免疫可预防 COVID-19。既往感染 SARS-CoV-2 个体接种灭活疫苗后，抗体应答的持续时间尚不清楚。收集了 58 名既往 SARS-CoV-2 感染个体和 25 名接种灭活疫苗的健康供体 (HD) 的血浆样本。使用化学发光免疫分析法测量针对 SARS-CoV-2 野生型和奥密克戎株以及核衣壳蛋白 (NP) 的中和抗体 (NAb) 和 S1 结构域特异性抗体。使用临床变量和 SARS-CoV-2 疫苗接种后不同时间点的抗体进行统计分析。在感染后 12 个月，既往 SARS-CoV-2 感染者中检测到针对野生型或奥密克戎株的 NAb（野生型：81%，几何平均 (GM)：20.3 AU/mL；奥密克戎：44%，GM：9.4 AU/mL），疫苗接种进一步增强了这些抗体水平（野生型：98%，GM：53.3 AU/mL；奥密克戎：75%，GM：27.8 AU/mL，在接种后 3 个月），明显高于接受第三剂灭活疫苗的 HD（野生型：85%，GM：33.6 AU/mL；奥密克戎：45%，GM：11.5 AU/mL）。既往感染个体的 NAb 水平在接种后 6 个月达到平台期，但 HD 的 NAb 水平持续下降。接种后 3 个月，既往感染个体的 NAb 水平与接种后 6 个月的 NAb 水平高度相关，与接种前的 NAb 水平弱相关。大多数个体的 NAb 水平显著下降，抗体衰减率与出院时血液中的中性粒细胞与淋巴细胞比值呈负相关。这些结果表明，灭活疫苗在接种后 9 个月内诱导既往感染个体产生了强大且持久的 NAb 应答。
