Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Center of Excellence in Osteoarthritis and Musculoskeleton, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
Hum Vaccin Immunother. 2023 Dec 15;19(3):2283916. doi: 10.1080/21645515.2023.2283916. Epub 2023 Nov 28.
Heterologous vaccination with inactivated vaccine followed by adenoviral vector-based vaccine has shown superiority in enhancing immune response compared to homologous primary series. However, data comparing immunity decline after a third booster following heterologous CoronaVac/ChAdOx-1nCov-19 has been limited. Here, we assessed neutralizing activity against omicron variant and T cell response at 3 months monitoring in 96 individuals who received ChAdOx-1nCov-19, BNT162b2, or mRNA-1273 as a third dose following heterologous CoronaVac/ChAdOx-1nCov-19. Comparing the antibody levels at 3 and 1 month(s) after the third booster, the results showed a persistence of anti-RBD IgG in all vaccine regimens, with the IgG level waning slower in the ChAdOx-1nCov-19 boosted group (geometric mean ratio (GMR): 0.64 (95%CI: 0.59-0.70)) compared to the BNT162b2 (0.34 (95%CI:0.31-0.38)) and mRNA-1273 boosted groups (0.32 (95%CI: 0.29-0.36)). Neutralizing activity against omicron BA.2 and BA.4/5 dropped by 1.2 to 1.5-fold but remained detectable, with the highest level observed in the mRNA-1273 group, followed by BNT162b2 and ChAdOx-1nCov-19 groups, respectively. Furthermore, the number of individuals with T cell reactivity decreased in BNT162b2 and mRNA-1273 groups, while it increased in ChAdOx-1nCov-19 group at 3-month post-boost compared to 1 month. Data on the durability of immune response could help comprehensively optimize the booster vaccine strategy.
异源接种灭活疫苗后再接种腺病毒载体疫苗，相较于同源基础免疫系列，在增强免疫应答方面显示出优势。然而，关于异源科兴/腺病毒新冠疫苗加强接种后第三针加强剂引发的免疫应答下降的数据有限。在此，我们评估了 96 名个体在接受异源科兴/腺病毒新冠疫苗加强接种后 3 个月监测时针对奥密克戎变异株的中和活性和 T 细胞反应，这些个体分别接受了 ChAdOx-1nCov-19、BNT162b2 或 mRNA-1273 作为第三针加强剂。比较第三针加强后 3 个月和 1 个月的抗体水平，结果显示所有疫苗方案均保持抗 RBD IgG 持久性，其中 ChAdOx-1nCov-19 加强组 IgG 水平下降较慢（几何平均比（GMR）：0.64（95%CI：0.59-0.70）），与 BNT162b2（0.34（95%CI：0.31-0.38））和 mRNA-1273 加强组（0.32（95%CI：0.29-0.36））相比。针对奥密克戎 BA.2 和 BA.4/5 的中和活性下降了 1.2 至 1.5 倍，但仍可检测到，mRNA-1273 组的水平最高，其次是 BNT162b2 组和 ChAdOx-1nCov-19 组。此外，与 1 个月相比，在 BNT162b2 和 mRNA-1273 组中，T 细胞反应性个体数量减少，而在 ChAdOx-1nCov-19 组中增加。关于免疫应答持久性的数据有助于全面优化加强疫苗策略。
