Ho Tzu-Chuan, Chen Yi-Ming Arthur, Chan Hung-Pin, Chang Chin-Chuan, Chuang Kuo-Pin, Lee Che-Hsin, Yuan Cheng-Hui, Tyan Yu-Chang, Yang Ming-Hui
Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic University, New Taipei City 242, Taiwan.
Vaccines (Basel). 2021 Oct 11;9(10):1163. doi: 10.3390/vaccines9101163.
Coronavirus Disease 2019 (COVID-19) pandemic, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become the global challenge. Reaching global herd immunity will help end the COVID-19 pandemic. However, vaccine shortage and vaccine hesitancy are the obstacles to achieve global herd immunity against SARS-CoV-2. The current homologous vaccine regimen is experimentally switching to heterologous vaccination at several study sites. However, the reactogenicity of heterologous ChAdOx1-S and mRNA vaccination against SARS-CoV-2 is still unclear. We have conducted a systematic review to summarize the current findings on the safety and immunogenicity of this heterologous vaccination and elucidate their implications against SARS-CoV-2. This systematic review was conducted by the guidelines of PRISMA. Articles were searched from PubMed and other sources (MedRixv and Google scholar) starting from 1 January to 5 September 2021. The search term was heterologous ChAdOx1-S and BNT162b2 or mRNA-1273 vaccination. Our review found that participants with ChAdOx1/BNT162b2, ChAdOx1-S/mRNA-1273 or BNT162b2/ChAdOx1-S did not have the serious adverse events seen with homologous vaccination. Participants with the heterologous regimen (ChAdOx1/BNT162b2, ChAdOx1-S/mRNA-1273 or BNT162b2/ChAdOx1-S), compared with those with two doses of ChAdOx1-S, have shown a more robust immune responses against SARS-CoV-2, such as higher levels of responsive antibodies or increased numbers of spike-specific T-cells. Nevertheless, these immune responses were slightly diminished in the recipients of BNT162b2/ChAdOx1-S. Also, the safety study of heterologous ChAdOx1-S/mRNA vaccination was based on small populations. Further studies to enclose diverse categories, such as race/ethnicity or geography, may be necessary. Overall, the heterologous immunization with ChAdOX1-S and the mRNA vaccine may improve the vaccine shortage related slow pace of reaching herd immunity, especially using the heterologous immunization with ChAdOx1-S/BNT162b2.
2019冠状病毒病（COVID-19）大流行由严重急性呼吸综合征冠状病毒2（SARS-CoV-2）引起，已成为全球挑战。实现全球群体免疫将有助于终结COVID-19大流行。然而，疫苗短缺和疫苗犹豫是实现针对SARS-CoV-2的全球群体免疫的障碍。目前，在几个研究地点，同源疫苗接种方案正在试验性地转向异源接种。然而，异源ChAdOx1-S和mRNA疫苗接种针对SARS-CoV-2的反应原性仍不明确。我们进行了一项系统综述，以总结关于这种异源疫苗接种安全性和免疫原性的当前研究结果，并阐明其对SARS-CoV-2的影响。本系统综述按照PRISMA指南进行。从2021年1月1日至9月5日在PubMed和其他来源（MedRixv和谷歌学术）搜索文章。搜索词为异源ChAdOx1-S和BNT162b2或mRNA-1273疫苗接种。我们的综述发现，接种ChAdOx1/BNT162b2、ChAdOx1-S/mRNA-1273或BNT162b2/ChAdOx1-S的参与者没有出现同源疫苗接种时所见的严重不良事件。与接种两剂ChAdOx1-S的参与者相比，采用异源接种方案（ChAdOx1/BNT162b2、ChAdOx1-S/mRNA-1273或BNT162b2/ChAdOx1-S）的参与者对SARS-CoV-2表现出更强的免疫反应，如更高水平的反应性抗体或刺突特异性T细胞数量增加。然而，在BNT162b2/ChAdOx1-S的接受者中，这些免疫反应略有减弱。此外，异源ChAdOx1-S/mRNA疫苗接种的安全性研究基于小群体。可能需要进一步开展涵盖不同类别（如种族/民族或地域）的研究。总体而言，ChAdOX1-S与mRNA疫苗的异源免疫接种可能改善与疫苗短缺相关的群体免疫达成速度缓慢的问题，尤其是采用ChAdOx1-S/BNT162b2的异源免疫接种。
