[nudephil (OP)]

Here's a question from Sian:

I was wondering if soluble antivirals could be added to the drinking water supply - like fluoride is for teeth - to protect a wider number of people from more severe symptoms of COVID-19?

What do you think?

[Petrochemicals]

Chlorine is an anti viral chemical but putting bleach in your body is not good as chlorine is harmful to all biological life. To use medication in the drinking water would be very expensive as most water goes down the drain.

[Bored chemist]

We don't have many antivirals that are much good.
Those we have are all more or less  toxic.
Filling the water supply with them would  almost certainly produce  an increase in resistance (like antibiotic resistance).