We have a protecting skin against the malicious world of bacteria and viruses. Our mind protects us against too many stimulants. Firewalls protect our digital systems. Social groups have a protecting codex against outsiders. Nations have the nationality as protection against intruders. Medieval cities had city walls against the intrusion of enemies. The earth has an ozone shield to protect life against an overflow of UV light.
An immune system is for the protection of an inner system against outer influences. Immune systems can have all kinds of appearances. Immune systems are crucial for the function of a system. However, immune systems can block something useful too. We might miss important information or stimuli. Immune systems shall be used carefully and considerably to avoid the lost of contact to the outer world. Immune systems secure the system on the costs of missing information. Balance the functions of the immune systems for a sustainable and efficient life. Do not overload social or national immune systems to avoid restrictions. Let the immune system flow and adjust according to the situation. Immune systems should be protecting and supporting the system and not encasing.