英国牛津大学Teresa Lambe和Katie J. Ewer合作取得最新进展。他们总结了在1/2期临床试验中，单剂ChAdOx1 nCoV-19（AZD1222）疫苗诱导的T细胞和抗体应答。该成果2020年12月7日发表在《自然-医学》杂志上。

他们最近报道了以单剂或两剂方案对ChAdOx1 nCoV-19疫苗（NCT04400838）7进行1/2期试验的初步安全性和免疫原性研究。耐受疫苗诱导出针对严重急性呼吸系统综合症冠状病毒2（SARS-CoV-2）刺突蛋白的中和抗体和抗原特异性T细胞。他们详细描述了在此试验中，对单剂量的ChAdOx1 nCoV-19疫苗接种后，对于18-55岁成年人长达8周的免疫应答进行探索性分析，证明了Th1偏向应答的诱导。其特征在于CD4 + T细胞分泌的干扰素-γ和肿瘤坏死因子-α细胞因子，并且主要产生IgG1和IgG3亚类抗体。还诱导了单功能、多功能和细胞毒性表型的CD8 + T细胞。

综上所述，这些结果表明，ChAdOx1 nCoV-19疫苗诱导了良好的免疫特性，推动了该候选疫苗向正在进行的2/3期临床试验评估疫苗效力的进程。

SARS-CoV-2是2019年冠状病毒病（COVID-19）的病原体，已引起全球性大流行，迫切需要安全有效的疫苗。Th1偏好的强烈T细胞反应可驱动保护性体液和细胞介导的免疫反应，并可能降低疾病增强的可能性。细胞毒性T细胞清除病毒感染的宿主细胞，并有助于控制感染。对感染SARS-CoV-2的患者的研究表明，从COVID-19的恢复中，体液和细胞介导的免疫反应均具有保护作用。ChAdOx1 nCoV-19（AZD1222）是一种SARS-CoV-2候选疫苗，包含表达全长SARS-CoV-2刺突蛋白的复制缺陷型猿猴腺病毒。

附：英文原文

Title: T cell and antibody responses induced by a single dose of ChAdOx1 nCoV-19 (AZD1222) vaccine in a phase 1/2 clinical trial

Author: Katie J. Ewer, Jordan R. Barrett, Sandra Belij-Rammerstorfer, Hannah Sharpe, Rebecca Makinson, Richard Morter, Amy Flaxman, Daniel Wright, Duncan Bellamy, Mustapha Bittaye, Christina Dold, Nicholas M. Provine, Jeremy Aboagye, Jamie Fowler, Sarah E. Silk, Jennifer Alderson, Parvinder K. Aley, Brian Angus, Eleanor Berrie, Sagida Bibi, Paola Cicconi, Elizabeth A. Clutterbuck, Irina Chelysheva, Pedro M. Folegatti, Michelle Fuskova, Catherine M. Green, Daniel Jenkin, Simon Kerridge, Alison Lawrie, Angela M. Minassian, Maria Moore, Yama Mujadidi, Emma Plested, Ian Poulton, Maheshi N. Ramasamy, Hannah Robinson, Rinn Song, Matthew D. Snape, Richard Tarrant, Merryn Voysey, Marion E. E. Watson, Alexander D. Douglas, Adrian V. S. Hill, Sarah C. Gilbert, Andrew J. Pollard, Teresa Lambe

Issue&Volume: 2020-12-17

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 2019 (COVID-19), has caused a global pandemic, and safe, effective vaccines are urgently needed1. Strong, Th1-skewed T cell responses can drive protective humoral and cell-mediated immune responses2 and might reduce the potential for disease enhancement3. Cytotoxic T cells clear virus-infected host cells and contribute to control of infection4. Studies of patients infected with SARS-CoV-2 have suggested a protective role for both humoral and cell-mediated immune responses in recovery from COVID-19 (refs. 5,6). ChAdOx1 nCoV-19 (AZD1222) is a candidate SARS-CoV-2 vaccine comprising a replication-deficient simian adenovirus expressing full-length SARS-CoV-2 spike protein. We recently reported preliminary safety and immunogenicity data from a phase 1/2 trial of the ChAdOx1 nCoV-19 vaccine (NCT04400838)7 given as either a one- or two-dose regimen. The vaccine was tolerated, with induction of neutralizing antibodies and antigen-specific T cells against the SARS-CoV-2 spike protein. Here we describe, in detail, exploratory analyses of the immune responses in adults, aged 18–55 years, up to 8 weeks after vaccination with a single dose of ChAdOx1 nCoV-19 in this trial, demonstrating an induction of a Th1-biased response characterized by interferon-γ and tumor necrosis factor-α cytokine secretion by CD4+ T cells and antibody production predominantly of IgG1 and IgG3 subclasses. CD8+ T cells, of monofunctional, polyfunctional and cytotoxic phenotypes, were also induced. Taken together, these results suggest a favorable immune profile induced by ChAdOx1 nCoV-19 vaccine, supporting the progression of this vaccine candidate to ongoing phase 2/3 trials to assess vaccine efficacy.

DOI: 10.1038/s41591-020-01194-5

Source: https://www.nature.com/articles/s41591-020-01194-5