From what I understand (my focus is Neuroscience, not Infectious Disease or Immunology), one of the main observed effects of COVID infection is inflammation of the vascular system [1]. Since the vascular system is responsible for maintaining pretty much all organs of the human body, infected individuals can exhibit a variety of symptoms based on the location of the inflammation. For example, neurological symptoms can indicate damage of the vessels around the brain [2].
This effect on the vascular system is not shared by the other pathogens/diseases you have listed, which (generally) target specific organs and/or tissues (respiratory, gastrointestinal, CNS) that are not as widespread and foundational as the vascular system. The variety of different possible targets (read: possible areas where the vascular system may suffer damage) is a very likely explanation for the variety of symptoms of COVID-19.
ZeroPointZero_ t1_j9adr7f wrote
Reply to Is COVID unique in the way it affects different individuals in such different ways? by stupidrobots
From what I understand (my focus is Neuroscience, not Infectious Disease or Immunology), one of the main observed effects of COVID infection is inflammation of the vascular system [1]. Since the vascular system is responsible for maintaining pretty much all organs of the human body, infected individuals can exhibit a variety of symptoms based on the location of the inflammation. For example, neurological symptoms can indicate damage of the vessels around the brain [2].
This effect on the vascular system is not shared by the other pathogens/diseases you have listed, which (generally) target specific organs and/or tissues (respiratory, gastrointestinal, CNS) that are not as widespread and foundational as the vascular system. The variety of different possible targets (read: possible areas where the vascular system may suffer damage) is a very likely explanation for the variety of symptoms of COVID-19.