Asymptomatic cases may be of great value in containing the pandemic

From the August 9, 2020 Washington Post:

So, when you start screening asymptomatic people who you think may have been exposed, you find lots of positives.  They are then called cases.  But they were not sick.  Did they spread the infection farther?  

If they did not spread it farther, then we can all stop worrying about asymptomatic spread, which is relatively rare in other viral infections.

These 'cases' add to the totals, but most importantly add to the immunes.  The asymptomatic cases won't catch it again during this pandemic, and they will also help to limit spread in their communities, by reducing the number of susceptible people. (I know the media claim there may be no immunity, but that is because researchers have not looked for T cell immunity, relying solely on antibody tests. Which is simply ignorant.)

Is anyone isolating virus from asymptomatic cases (especially from those prisons and Tyson food factories) to learn what the mutations are that led to so many asymptomatic cases, and see if these viruses might serve as attenuated strains for a vaccine?

Once T cell tests are widely available, we will be able to find out how many people are really immune.