I know that common infections can be fatal for people with very weak immune systems. But if most symptoms are caused by our immune system’s response to the infection instead of the infection itself, do immunocompromised people still have symptoms?
In: Biology
They may, depending on the strain of the virus and how exactly the infection progresses.
Without the immune system to fight and eventually kill it off, the virus is going to replicate unchecked inside the body. Viral replication happens by the virus infiltrating the cells of the host body and hijacking the cell machinery inside to produce copies using the virus’ DNA rather than the host’s own DNA, generally until the cell eventually bursts and releases all the produced copies to go on and infect other cells. This kills the infected cell, naturally.
As the infection grows, this leads to more and more dead cells in the host body, eventually outpacing the body’s own ability to replace them with fresh cells. How this manifest in the host body’s health depends on where the infection is localised. If it is mostly cells in the lungs that are affected for example, the host would likely start to experience symptoms of respiratory difficulties like shortness of breath or eventually the inability to breathe at all as a result of the damage rather than any immune response.
A symptom is really just any measurable deviation from how the body normally functions, and the things the immune system commonly does often just serve as highly-visible-but-harmless signs early in the process. The really bad stuff is that which only show the symptoms ‘Cascading organ failure’ and ‘Death’
It’s like you said, depending on the level of immunodeficiency and/or the infection itself, they will have none to very mild of the “normal” symptoms… but they might die instead.
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