Laopajon Witida, Deesomchok Athavudh, Chaiwong Warawut, Takheaw Nuchjira, Pata Supansa, Duangjit Pilaiporn, Inchai Juthamas, Pothirat Chaicharn, Bumroongkit Chaiwat, Theerakittikul Theerakorn, Limsukon Atikun, Tajarernmuang Pattraporn, Niyatiwatchanchai Nutchanok, Trongtrakul Konlawij, Chuensirikulchai Kantinan, Cheyasawan Passaworn, Liwsrisakun Chalerm, Kasinrerk Watchara
Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.
Biomedical Technology Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at the Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.
Infect Chemother. 2025 Jun;57(2):274-287. doi: 10.3947/ic.2024.0145. Epub 2025 Apr 16.
Although infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) could induce natural immunity, previously infected individuals were suggested to have additional vaccination to enhance immune responses against the new variants of concern (VOCs). In this study, we determined the effects of a single dose of inactivated vaccine and viral vector-based vaccine on the neutralizing antibody (NAb) and T cell responses against the wild type (WT) and VOCs in the post-infection individuals.
The levels of NAb and specific T cell responses against the WT and VOCs of the previously infected individuals were determined before and after vaccination with a single dose of CoronaVac (CoVac) or ChAdOx-1 (ChAd) vaccine.
Eighteen subjects, with nine participants in each vaccination group, were recruited in this study. The CoVac group was significantly older (53.3±12.8 34.4±14.0 years, =0.009) and had shorter disease-vaccination time (111.0 186.0 days, <0.001) than the ChAd group. Before vaccination, both groups had median NAb against WT, Alpha, Beta, and Delta variants, but not Omicron BA.4 and.5 variants, above the detection threshold. After vaccination, the NAbs and the CD4 and CD8 T-cell responses against the tested variants were demonstrated. However, the NAb in the CoVac arm was lower than in the ChAd arm. In contrast, the CoVac vaccine-induced T-cell responses are better than the ChAd vaccine.
In post-SARS-CoV-2 infection, ChAd vaccination induced a better antibody response, but the CoVac vaccine induced greater T-cell responses. Vaccination is valuable in boosting immunity, particularly against some VOCs, in individuals with prior SARS-CoV-2 infection.
This study was registered by the Clinical Trials Registry TCTR20210822002.
尽管感染严重急性呼吸综合征冠状病毒2（SARS-CoV-2）可诱导自然免疫，但先前感染过的个体仍建议接种额外疫苗以增强针对新出现的关注变异株（VOC）的免疫反应。在本研究中，我们确定了单剂量灭活疫苗和基于病毒载体的疫苗对感染后个体针对野生型（WT）和VOC的中和抗体（NAb）及T细胞反应的影响。
在用单剂量科兴新冠疫苗（CoronaVac，简称CoVac）或牛津-阿斯利康新冠疫苗（ChAdOx-1，简称ChAd）进行疫苗接种前后，测定先前感染个体针对WT和VOC的NAb水平及特异性T细胞反应。
本研究招募了18名受试者，每个疫苗接种组各9名参与者。CoVac组的年龄显著大于ChAd组（53.3±12.8岁对34.4±14.0岁，P=0.009），且疾病至疫苗接种的时间短于ChAd组（111.0天对186.0天，P<0.001）。接种疫苗前，两组针对WT、阿尔法、贝塔和德尔塔变异株的NAb中位数均高于检测阈值，但针对奥密克戎BA.4和BA.5变异株的NAb中位数未高于检测阈值。接种疫苗后，检测到针对所测试变异株的NAb以及CD4和CD8 T细胞反应。然而，CoVac组的NAb低于ChAd组。相比之下，CoVac疫苗诱导的T细胞反应优于ChAd疫苗。
在SARS-CoV-2感染后，ChAd疫苗接种诱导了更好的抗体反应，但CoVac疫苗诱导了更强的T细胞反应。疫苗接种对于增强先前感染SARS-CoV-2个体的免疫力具有重要价值，尤其是针对某些VOC。
本研究已在泰国临床试验注册中心（Clinical Trials Registry TCTR）注册，注册号为TCTR20210822002。
