Before revision:  This seems indefensible unless one assumes that (a) there is only a small chance of any future vaccine and no future improvements in treatment or in non-medical interventions , (b) that COVID-19 will inevitably continue to propagate until herd immunity is reached .
After revision:  This seems indefensible unless one assumes that (a) there is only a small chance of any effective vaccine or improved medical or social interventions for the foreseeable future , (b) that COVID-19 will inevitably continue to propagate until herd immunity is reached .