Nonlocal reaction–diffusion model of viral evolution: emergence of virus strains

This work is devoted to the investigation of virus quasi-species evolution and diversification due to mutations, competition for host cells, and cross-reactive immune responses. The model consists of a nonlocal reaction–diffusion equation for the virus density depending on the genotype considered to be a continuous variable and on time. This equation contains two integral terms corresponding to the nonlocal effects of virus interaction with host cells and with immune cells. In the model, a virus strain is represented by a localized solution concentrated around some given genotype. Emergence of new strains corresponds to a periodic wave propagating in the space of genotypes. The conditions of appearance of such waves and their dynamics are described.The research was funded by the Russian Science Foundation (Grant no. 18-11-00171) to N.B., G.B., A.M. and V.V. V.P. and V.V. were partially supported by the “RUDN University Program 5-100”. A.M. was also supported by a grant from the Spanish Ministry of Economy, Industry and Competitiveness and FEDER grant no. SAF2016-75505-R (AEI/MINEICO/FEDER, UE) and the “Maria de Maeztu” Programme for Units of Excellence in R&D (MDM-2014-0370)