Kaur Gurpreet, Singh Sanpreet, Nanda Sidhanta, Zafar Mohammad Adeel, Malik Jonaid Ahmad, Arshi Mohammad Umar, Lamba Taruna, Agrewala Javed Naim
Immunology Laboratory, Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar 140001, India.
Immunology Laboratory, Division of Cell Biology and Immunology, CSIR-Institute of Microbial Technology, Chandigarh 160036, India.
Vaccines (Basel). 2022 Jun 23;10(7):1006. doi: 10.3390/vaccines10071006.
The Bacille Calmette-Guérin or BCG vaccine, the only vaccine available against can induce a marked Th1 polarization of T-cells, characterized by the antigen-specific secretion of IFN-γ and enhanced antiviral response. A number of studies have supported the concept of protection by non-specific boosting of immunity by BCG and other microbes. BCG is a well-known example of a trained immunity inducer since it imparts 'non-specific heterologous' immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the recent pandemic. SARS-CoV-2 continues to inflict an unabated surge in morbidity and mortality around the world. There is an urgent need to devise and develop alternate strategies to bolster host immunity against the coronavirus disease of 2019 (COVID-19) and its continuously emerging variants. Several vaccines have been developed recently against COVID-19, but the data on their protective efficacy remains doubtful. Therefore, urgent strategies are required to enhance system immunity to adequately defend against newly emerging infections. The concept of trained immunity may play a cardinal role in protection against COVID-19. The ability of trained immunity-based vaccines is to promote heterologous immune responses beyond their specific antigens, which may notably help in defending against an emergency situation such as COVID-19 when the protective ability of vaccines is suspicious. A growing body of evidence points towards the beneficial non-specific boosting of immune responses by BCG or other microbes, which may protect against COVID-19. Clinical trials are underway to consider the efficacy of BCG vaccination against SARS-CoV-2 on healthcare workers and the elderly population. In this review, we will discuss the role of BCG in eliciting trained immunity and the possible limitations and challenges in controlling COVID-19 and future pandemics.
卡介苗（BCG）疫苗是唯一可预防[此处原文缺失疾病名称]的疫苗，它能诱导T细胞显著向Th1极化，其特征是抗原特异性分泌γ干扰素并增强抗病毒反应。许多研究支持了卡介苗和其他微生物通过非特异性增强免疫力来提供保护的概念。卡介苗是诱导训练有素的免疫力的一个著名例子，因为它能赋予针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2，即导致近期大流行的病毒）的“非特异性异源”免疫力。SARS-CoV-2在全球范围内导致的发病率和死亡率仍在持续激增。迫切需要设计和开发替代策略来增强宿主对2019冠状病毒病（COVID-19）及其不断出现的变体的免疫力。最近已经研发出几种针对COVID-19的疫苗，但其保护效力的数据仍令人怀疑。因此，需要紧急策略来增强全身免疫力，以充分抵御新出现的感染。训练有素的免疫力概念可能在预防COVID-19中发挥关键作用。基于训练有素的免疫力的疫苗能够促进超出其特定抗原的异源免疫反应，这在疫苗保护能力存疑时，对于抵御诸如COVID-19这样的紧急情况可能特别有帮助。越来越多的证据表明卡介苗或其他微生物对免疫反应有有益的非特异性增强作用，这可能预防COVID-19。目前正在进行临床试验，以评估卡介苗接种对医护人员和老年人群预防SARS-CoV-2的效果。在这篇综述中，我们将讨论卡介苗在引发训练有素的免疫力方面的作用，以及在控制COVID-19和未来大流行中可能存在的局限性和挑战。
