“…The main causes of utilizing the fractional-order models (FDMs) is linked to frameworks that have history, memory, or effects of non-locality that can be found in several biological paradigms which shows slowly the realistic double phases refusing manner of infection or diseases. It has been investigated in several scientific papers in the literature that the generalization of the mathematical integer order systems by fractional derivative models the natural manner in a very formal technique for instance in the method suggested in [19] by Akbari et al, in [20] , [21] , [22] , [23] , [24] , [25] , [26] , [16] by Etemad et al, in [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] by Baleanu et al, in [36] , [37] by and in [38] by Talaee et al Latterly, several researchers have been issued on the concept of fractional derivative operator called “ Caputo-Fabrizio operator ” (see for instance, [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] ). Different mathematical paradigms are utilized for simulating COVID-19 transition (see for instance, [49] , [50] , [51] , [52] , [53] , [54] , [55] ).…”