It's important to note that this was a study of 87 people. The part that stands out to me is their findings about inactive coronaviruses particles in the GI tract, because I've read that animal studies have demonstrated corona stays dormant and more deadly versions mutate within the host's gut.
From the article: "The scientists went on to show that tiny amounts of coronavirus, or protein fragments from inactive virus particles, lurked in patients’ intestines and apparently helped to maintain the immune system’s memory.
The remnants of the virus are not thought to be harmful."
"[M]ost infections are with relatively harmless strains of feline coronavirus. Unfortunately, this initial benign infection may later mutate to cause FIP in some cats. Even with the more harmful strains, apparently healthy cats may be carriers of the virus, and may shed the virus without ever showing signs of disease. Many cats that develop FIP have no history of contact with other cats showing clinical signs of FIP.
The virus can remain dormant or inactive in the body for months to years before the cat eventually develops disease.
Once disease develops, most individuals deteriorate rapidly, although some cats remain normal for several weeks.
Unfortunately, the disease will eventually result in death in almost every case.
FIP is associated with a viral infection called feline coronavirus. There are many different strains of feline coronavirus, which differ in their ability to cause disease. Feline enteric coronavirus strains can mutate to the more harmful type of virus and cause FIP disease. Many of the clinical...
vcahospitals.com