Bruh, measles has most of the same symptoms. Similar symptoms =/= same virus.
It isn't a "cold" or "flu". The problem is that "coronavirus" is an entire family of viruses, and that the antibodies these tests look for are not designed to be specific to a particular species of virus. Antibodies typically follow an "induced fit" rule, meaning that if a virus is "close enough", they will attach to said virus. Since SARS1, SARS2, MERS, and the four or so different human coronavirus species that can cause the common cold are all part of this same family, their surface membranes are likely similar enough that these antibodies will react the same way to all of them.
Bruh, measles has most of the same symptoms. Similar symptoms =/= same virus.
It isn't a "cold" or "flu". The problem is that "coronavirus" is an entire family of viruses, and that the antibodies these tests look for are not designed to be specific to a particular species of virus. Antibodies typically follow an "induced fit" rule, meaning that if a virus is "close enough", they will attach to said virus. Since SARS1, SARS2, MERS, and the four or so different human coronavirus species that can cause the common cold are all part of this same family, their surface membranes are likely similar enough that these antibodies will react the same way to all of them.