Table 1.

Summary of key perspectives on immune equilibrium.

Author(s)	key perspectives	References
Elie Metchnikoff	The author demonstrated the existence of phagocytes and pointed out that the symbiotic relationship between microbes and their hosts emerges from a balanced contention between these microorganisms and the phagocytes.	(14, 15)
Theobald Smith	The author believed that, in the evolutionary process of parasite-host interactions, the two parties gradually tend towards equilibrium, and infectious diseases represented a manifestation of the imbalance in the struggle between parasites and hosts.	(40)
Hans Zinsser	The author believed that the core of the mutual adaptation between parasites and hosts lies in the balance of their antagonistic interactions.	(41)
Felix d’Herelle	The author, through research on bacteriophages, demonstrated that both pathogens and hosts have significant abilities to adapt to each other’s increasing virulence and resistance, eventually leading to a perfectly balanced interaction between them.	(42, 43)
Niels Jerne	The author believed that the fundamental role of the immune system was to restore the disrupted balance by generating an appropriate antibody response.	(44)
Macfarlane Burnet	The author identified an intrinsic tendency in both microbial and immune cells to seek ecological balance. Thus, he proposed a dynamic equilibrium mechanism, regulating interactions between immune and non-immune cells by adjusting cell quantity and composition.	(10, 17)
Bartlomiej Swiatczak	The author systematically summarized the theory of immune balance, proposing that the immune system is not a killer of non-self entities, but rather a peacemaker that helps establish harmony with the environment.	(10)
Gérard Eberl	The author proposed that the immune system maintains a dynamic balance among four mutually inhibitory responses: Type 1 (targeting intracellular threats like viruses), Type 2 (addressing large parasites), Type 3 (focusing on extracellular microorganisms), and Type 4 (protecting sensitive tissues by secreting substances such as IgA).	(11)
Joseph M. Cicchese et al.	The authors believed that the dynamics of pro- and anti-inflammatory immune responses influence disease progression. These responses can lead to outcomes such as high pathogen burden, severe tissue damage, cleared infection with restored inflammation levels, or a balanced response that controls pathogen growth and limits host damage.	(12)
Daniil Shevyrev et al.	The authors suggested that immune system equilibrium is dynamically maintained by genetic HLA variants, which shape TCR repertoires and individualize immune responses. Disruptions in this balance, leading to various diseases, are associated with changes in antigen presentation, T- and B-cell repertoires, and cell specialization.	(13)