Department of Pulmonary and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China.
Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China.
Signal Transduct Target Ther. 2024 Feb 14;9(1):41. doi: 10.1038/s41392-024-01751-1.
Vaccines have proven effective in protecting populations against COVID-19, including the recombinant COVID-19 vaccine (Sf9 cells), the first approved recombinant protein vaccine in China. In this positive-controlled trial with 85 adult participants (Sf9 cells group: n = 44; CoronaVac group: n = 41), we evaluated the safety, immunogenicity, and protective effectiveness of a heterologous boost with the Sf9 cells vaccine in adults who had been vaccinated with the inactivated vaccine, and found a post-booster adverse events rate of 20.45% in the Sf9 cells group and 31.71% in the CoronaVac group (p = 0.279), within 28 days after booster injection. Neither group reported any severe adverse events. Following the Sf9 cells vaccine booster, the geometric mean titer (GMT) of binding antibodies to the receptor-binding domain of prototype SARS-CoV-2 on day 28 post-booster was significantly higher than that induced by the CoronaVac vaccine booster (100,683.37 vs. 9,451.69, p < 0.001). In the Sf9 cells group, GMTs of neutralizing antibodies against pseudo SARS-CoV-2 viruses (prototype and diverse variants of concern [VOCs]) increased by 22.23-75.93 folds from baseline to day 28 post-booster, while the CoronaVac group showed increases of only 3.29-10.70 folds. Similarly, neutralizing antibodies against live SARS-CoV-2 viruses (prototype and diverse VOCs) increased by 68.18-192.67 folds on day 14 post-booster compared with the baseline level, significantly greater than the CoronaVac group (19.67-37.67 folds). A more robust Th1 cellular response was observed with the Sf9 cells booster on day 14 post-booster (mean IFN-γ+ spot-forming cells per 2 × 10 peripheral blood mononuclear cells: 26.66 vs. 13.59). Protective effectiveness against symptomatic COVID-19 was approximately twice as high in the Sf9 cells group compared to the CoronaVac group (68.18% vs. 36.59%, p = 0.004). Our study findings support the high protective effectiveness of heterologous boosting with the recombinant COVID-19 vaccine (Sf9 cells) against symptomatic COVID-19 of diverse SARS-CoV-2 variants of concern, while causing no apparent safety concerns.
疫苗已被证明能有效保护人群免受 COVID-19 感染，包括重组 COVID-19 疫苗（Sf9 细胞），这是中国批准的首个重组蛋白疫苗。在这项针对 85 名成年参与者的阳性对照试验中（Sf9 细胞组：n=44；CoronaVac 组：n=41），我们评估了在已接种灭活疫苗的成年人中使用 Sf9 细胞疫苗进行异源加强免疫的安全性、免疫原性和保护效力，发现 Sf9 细胞组的加强后不良事件发生率为 20.45%，CoronaVac 组为 31.71%（p=0.279），均在加强后 28 天内发生。两组均未报告任何严重不良事件。Sf9 细胞疫苗加强后，第 28 天的受体结合域结合抗体几何平均滴度（GMT）明显高于 CoronaVac 疫苗加强后（100683.37 比 9451.69，p<0.001）。在 Sf9 细胞组中，针对假 SARS-CoV-2 病毒（原型和多种关注变异株[VOC]）的中和抗体 GMT 在加强后第 28 天比基线水平增加了 22.23-75.93 倍，而 CoronaVac 组仅增加了 3.29-10.70 倍。同样，在加强后第 14 天，针对活 SARS-CoV-2 病毒（原型和多种 VOC）的中和抗体也比基线水平增加了 68.18-192.67 倍，明显高于 CoronaVac 组（19.67-37.67 倍）。在加强后第 14 天，Sf9 细胞组观察到更强的 Th1 细胞反应（每 2×10 个外周血单个核细胞的 IFN-γ+斑点形成细胞：26.66 比 13.59）。与 CoronaVac 组相比，Sf9 细胞组对有症状 COVID-19 的保护效力约高两倍（68.18%比 36.59%，p=0.004）。我们的研究结果支持使用重组 COVID-19 疫苗（Sf9 细胞）进行异源加强免疫对多种关注的 SARS-CoV-2 VOC 引起的有症状 COVID-19 具有高保护效力，同时没有明显的安全性问题。
