it will depend on the small print on your tickets – some tickets (especially bargain versions) do not permit changes/refunds.  Basically, if the flight you were booked on still flies as per the schedule in April, then it will be you that cancelled the flight and the airline are not liable to refund anything.

However, if there are regulatory reasons, i.e. a government ban on travel, then normally the airlines will allow you to rebook to a later date or some are even offering vouchers; not many are offering cash refunds at the moment.  My advice is to speak to the airline and see what they say.