It's a difficult one this - I have around €4,000 in airline bookings with Lufthansa, Aer Lingus, Easyjet and Ryanair.
I've taken a voucher with Lufthansa because I'm not even sure the airline will still be flying if they were to pay out all their refunds.The only drawback is that new flights have to be taken within a year and who would want to be flying within a year if no vaccine has been found.
Ryanair and Aer Lingus I'll also be happy with a voucher as I fly with them a lot and will be able to use them.
I just don't know why the airlines offer vouchers than can be used up to say three years from now.