Hjelholt Astrid Johannesson, Bergh Cecilia, Bhatt Deepak L, Fröbert Ole, Kjolby Mads Fuglsang
Steno Diabetes Center Aarhus, Aarhus University Hospital, Palle Juul-Jensens Boulevard 11, 8200 Aarhus N, Denmark.
Department of Biomedicine, Aarhus University, Høegh-Guldbergs Gade 10, 8000 Aarhus, Denmark.
Vaccines (Basel). 2023 Aug 25;11(9):1419. doi: 10.3390/vaccines11091419.
Influenza vaccines are designed to mimic natural influenza virus exposure and stimulate a long-lasting immune response to future infections. The evolving nature of the influenza virus makes vaccination an important and efficacious strategy to reduce healthcare-related complications of influenza. Several lines of evidence indicate that influenza vaccination may induce nonspecific effects, also referred to as heterologous or pleiotropic effects, that go beyond protection against infection. Different explanations are proposed, including the upregulation and downregulation of cytokines and epigenetic reprogramming in monocytes and natural killer cells, imprinting an immunological memory in the innate immune system, a phenomenon termed "trained immunity". Also, cross-reactivity between related stimuli and bystander activation, which entails activation of B and T lymphocytes without specific recognition of antigens, may play a role. In this review, we will discuss the possible nonspecific effects of influenza vaccination in cardiovascular disease, type 1 diabetes, cancer, and Alzheimer's disease, future research questions, and potential implications. A discussion of the potential effects on infections by other pathogens is beyond the scope of this review.
流感疫苗旨在模拟自然感染流感病毒的过程，并激发对未来感染的持久免疫反应。流感病毒不断演变的特性使得接种疫苗成为减少流感相关医疗并发症的一项重要且有效的策略。多项证据表明，流感疫苗接种可能会引发非特异性效应，也称为异源或多效性效应，这些效应超出了预防感染的范畴。人们提出了不同的解释，包括细胞因子的上调和下调以及单核细胞和自然杀伤细胞中的表观遗传重编程，从而在先天免疫系统中留下免疫记忆，这一现象被称为“训练有素的免疫”。此外，相关刺激与旁观者激活之间的交叉反应（即B和T淋巴细胞在未特异性识别抗原的情况下被激活）可能也起了作用。在这篇综述中，我们将讨论流感疫苗接种在心血管疾病、1型糖尿病、癌症和阿尔茨海默病中可能产生的非特异性效应、未来的研究问题以及潜在影响。关于对其他病原体感染的潜在影响的讨论不在本综述范围内。
