Flu season started a bit early this year - and peaked earlier. It usually peaks around now or even march.
Coronavirus didn't "just" start - it started right around the same time as influenza - and travelers from China likely brought it to Seattle before 2019 was even over. Test kits were defective - if tests were even run (500 total before this week.) There are probably thousands of people who already have the virus here in the states - some of which probably have zero symptoms.
People who panic don't help anything, obviously. If you are immune-compromised in any way I'd take extra precautions. I'd avoid tight places with large crowds for the next 30-60 days.
I was in Costco and target today and it looked like a war zone. Even all the cold/flu med was sold out at Target. Wild.
Regarding your husband's stock retirement: I hope he doesn't have everything in one stock? The 11 dollars a share loss this week makes little sense out of context here. Overall most diversified portfolios are down 10-15% this week - but the stock market has been parabolic since October. My portfolio is right back where it was 4 months ago, but I'm sure we haven't hit the lows yet.
The real question is: When is the right time to start buying?