美国亚利桑那大学Deepta Bhattacharya等研究人员合作揭示患有实体瘤的成年人对两剂和三剂BNT162b2 mRNA疫苗的免疫反应。2021年9月30日，《自然—医学》杂志在线发表了这项成果。

研究人员比较了正在接受积极的细胞毒性抗癌治疗的实体瘤患者（n=53）与没有癌症的对照组参与者（n=50）对BNT162b2 mRNA疫苗的免疫反应。在第一次免疫后，67%的癌症患者检测到中和抗体，随后在第二次免疫后，中位滴度增加了三倍。在突刺蛋白特异性血清抗体和T细胞方面也观察到类似的模式，但相对于对照组而言，这些反应的程度都有所减弱。在大多数癌症患者中，研究人员检测到突刺受体结合域和其他S1特异性记忆B细胞亚群是对额外免疫反应的潜在预测因素。

因此，研究人员为20名癌症队列参与者启动了一项1期试验，即第三剂BNT162b2疫苗（NCT04936997）；主要结果是免疫反应，次要结果是安全性。在第三次免疫接种后1周，16名参与者的中和抗体反应中位数增加了3倍，但T细胞反应未见改善。不良事件是温和的。这些结果表明，第三剂量的BNT162b2是安全的，能提高对SARS-CoV-2的体液免疫力，对正在接受化疗的癌症患者可能有免疫上的好处。

据介绍，SARS-CoV-2疫苗已显示出很高的疗效，但免疫功能低下的参与者被排除在对照的临床试验之外。

附：英文原文

Title: Immune responses to two and three doses of the BNT162b2 mRNA vaccine in adults with solid tumors

Author: Shroff, Rachna T., Chalasani, Pavani, Wei, Ran, Pennington, Daniel, Quirk, Grace, Schoenle, Marta V., Peyton, Kameron L., Uhrlaub, Jennifer L., Ripperger, Tyler J., Jergovi, Mladen, Dalgai, Shelby, Wolf, Alexander, Whitmer, Rebecca, Hammad, Hytham, Carrier, Amy, Scott, Aaron J., Nikolich-ugich, Janko, Worobey, Michael, Sprissler, Ryan, Dake, Michael, LaFleur, Bonnie J., Bhattacharya, Deepta

Issue&Volume: 2021-09-30

Abstract: Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have shown high efficacy, but immunocompromised participants were excluded from controlled clinical trials. In this study, we compared immune responses to the BNT162b2 mRNA Coronavirus Disease 2019 vaccine in patients with solid tumors (n=53) who were on active cytotoxic anti-cancer therapy to a control cohort of participants without cancer (n=50). Neutralizing antibodies were detected in 67% of patients with cancer after the first immunization, followed by a threefold increase in median titers after the second dose. Similar patterns were observed for spike protein-specific serum antibodies and T cells, but the magnitude of each of these responses was diminished relative to the control cohort. In most patients with cancer, we detected spike receptor-binding domain and other S1-specific memory B cell subsets as potential predictors of anamnestic responses to additional immunizations. We therefore initiated a phase 1 trial for 20 cancer cohort participants of a third vaccine dose of BNT162b2 (NCT04936997); primary outcomes were immune responses, with a secondary outcome of safety. At 1 week after a third immunization, 16 participants demonstrated a median threefold increase in neutralizing antibody responses, but no improvement was observed in T cell responses. Adverse events were mild. These results suggest that a third dose of BNT162b2 is safe, improves humoral immunity against SARS-CoV-2 and could be immunologically beneficial for patients with cancer on active chemotherapy.

DOI: 10.1038/s41591-021-01542-z

Source: https://www.nature.com/articles/s41591-021-01542-z