SARS-CoV-2 evolution and evasion from multiple antibody treatments in a cancer patient

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in immunocompromised patients may lead to accelerated viral mutation rate, immune evasion and persistent viral shedding over many months. Here we report the case of a severely immunocompromised cancer patient infected with the Delta variant of SARS-CoV-2 for over 8 months. Genome sequencing of samples taken after repeated monoclonal antibody treatments reveal the emergence and accumulation of mutations enabling escape from neutralization by antibodies. Mutations emerging in accessory and non-structural viral proteins target specific residues of immunomodulatory domains, potentially leading to loss of some functions, while preserving others. The mutated virus managed to completely overcome neutralization by monoclonal antibodies while remaining viable and infective. Our results suggest that the loss of specific immunomodulatory viral functions might confer a selective advantage in immunocompromised hosts. We also compare between mutations emerging in the presence and absence of neutralizing antibodies. Highlights SARS-CoV-2 undergoes rapid evolution in an immunocompromised, chronically infected cancer patient, overcoming neutralization by two monoclonal antibody cocktail treatments Receptor binding domain (RBD) mutations emerging after monoclonal antibody treatment enable effective escape from neutralization in the absence of adaptive immunity Some emerging mutations are predicted to disrupt immunomodulatory viral proteins, including prevention of ORF8 homodimerization, mis-localization of ORF3a in host cells and alteration of the host-suppressive function of NSP1