The best way to prevent spreading diseases at the office is to not require your employees to go to the office - assuming WFH is compatible with the company's business.

I work at a FAANG company which was aggressively opposed to WFH before the covid-19 crisis. As matter of fact, I recently changed teams within said company and during the informational interview I asked about the team's policy on WFH - the answer was that "our team has a strong 'collaborative in-the-office' culture, so we don't encourage WFH"

I am not kidding, we're talking about one of the most advanced companies in history and they required domestic travel+hotel for trivial half-day, mostly passive interview training that could have been done easily over teleconference, that's how much this company values physical presence.

Fast forward a few months, everybody is WFH in the company and the sky hasn't fallen. Actually, my productivity vastly increased because I'm fortunate to have a solid WFH environment at home (despite kids/wife around).

While I'm not proposing mandatory WFH for tech companies, neither saying that it works for everybody, I believe our top companies could lead and finally allow people who demonstrate that they can be productive at home to just stay home - permanently.