If the airline cancels the flight then yes, you're definitely entitled to a refund.
If you cancel your trip due to your locale's stay at home order but the flight itself is not canceled then your situation is less clear. Some airlines may offer a full refund, others may not. I don't think they're legally obligated to do so.
Trickier still is a situation like the Tokyo Olympics - postponed, but the original date is still far enough in the future that it isn't known whether the virus will still be an issue or whether the airlines' flight schedules will be back to normal. In that case I expect the best you can do is a voucher for the ticketed value minus a cancellation fee.