It is not hard to do the sequencing to find candidate attenuated strains (you are just looking for strains with deletions in key genes). The more difficult part

It is not hard to do the sequencing to find candidate attenuated strains (you are just looking for strains with deletions in key genes). The more difficult part is all the contact tracing in the area around where the strain is first found to check if the strain really is attenuated. The ideal outcome is you find a strain with a deletion and you then test everyone in the area and you find 10,000 more people infected with the strain that have only a mild case and none of these people are in the hospitals. This strain would be very valuable to have.