Here is a story about it, I guess it might be because he can.
The antibody treatment that Abbott is receiving — a cocktail made by Regeneron Pharmaceuticals — is one that Abbott has increasingly promoted. Hoping to prevent hospitalizations and reserve hospital capacity for the most serious cases, Texas recently opened nine antibody infusion centers throughout the state that use the Regeneron antibodies.
It was not exactly clear why Abbott was receiving the Regeneron treatment if he was not experiencing symptoms. The Regeneron antibodies are recommended to treat "mild to moderate COVID-19" in people 12 years and older who have tested positive and "are at high risk for progressing to severe COVID-19."
https://www.texastribune.org/2021/08...ositive-covid/
