Clearing vaccine-derived poliovirus infection following hematopoietic stem cell transplantation: A case report and review of literature

The use of oral poliovirus vaccine in a worldwide scale has led to a 99.9% decrease in annual incidence of wild-type poliomyelitis and the eradication of serotype 2 poliovirus. However, the emergence of vaccine-derived polioviruses (VDPVs) is endangering the eradication program. Patients with combined immunodeficiencies are at increased risk of both vaccine-associated poliomyelitis and prolonged asymptomatic infection with immunodeficiency-associated VDPVs (iVDPVs). Herein, we present a severe combined immunodeficiency patient with prolonged and asymptomatic iVDPVinfection. He continued to shed poliovirus during immunoglobulin replacement therapy and cleared the infection following successful hematopoietic stem cell transplantation (HSCT). To explain the efficiency of HSCT in clearing the infection, we reviewed the literature for all reports of HSCT in iVDPV-excreting patients and discussed novel ideas about the role of different immune mechanisms, including cell-mediated interactions, in mounting immune responses against poliovirus infections. This study could provide further insights into the immune mechanisms contributing to the clearance of enteroviral infections.