Question

the immune system creates antibodies and memory cells against a specific pathogen only after it has already been exposed to and fought off that pathogen before.
so, if you take a sample of somebodys blood and they already have antibodies against coronavirus, what does this mean?
the person has never had covid
the presence of antibodies in their blood has no relation to whether or not they have had the disease before
the person has already had covid

Explanation:

The immune system makes antibodies after exposure to a pathogen. So having coronavirus - antibodies means past exposure.

Answer:

The person has already had COVID