Abstract: Background Rare cases of immunodeficiency disease-related vaccine-derived poliomyelitis (iVAPP) have been reported in China. Objective To analyze the clinical features, immunodeficiency phenotype, treatment as well as prognosis among different iVAPP patients. Design Case series report. Methods Retrospective analysis was performed for the clinical data of 4 children with iVAPP admitted to Department of Clinical Immunology at Children's Hospital of Fudan University from May 2018 to June 2023. The intercepted information from medical records included poliovirus (PV) vaccination, clinical manifestations, immune-related indicators, etiological test results, treatment, outcome and muscle strength recovery. Main outcome measures Clinical manifestations and immunology-related indicators. Results All 4 patients with iVAPP were boys. Their paralysis symptoms were presented at 4-7 months after taking OPV, and the first dose was received at 3 months of age. Case 1, 2, 4 received 1, 2, and 3 doses of OPV respectively, and case 3 received 2 doses of OPV and 1 dose of IPV. Two cases of combined immunodeficiency-related vaccine-derived polio (CID-VAPP) were admitted to the hospital due to lung infection and axillary lymph node inflammation with severely reduced counts of T and B cells. Their paralysis of multiple limbs and muscle weakness of multiple limbs could not be relieved by active treatment. The infections involved multiple sites and were caused by various pathogens. Mycobacterium tuberculosis complex and severe pneumonia were found. Deaths occurred within the first year of life due to severe infections. The other 2 cases were primary antibody deficiency disease (PAD)-VAPP, who were admitted to the hospital at the age of 12 months and 9 months respectively due to limb disability, showing a decrease in the number of B cells as well as impaired antibody secretion. The symptoms of limb paralysis involved one or more sides of the body, and the muscle strength could return to normal after treatment, with mild infection symptoms and a good prognosis. Conclusion Intaking OPV may lead to iVAPP in both CID and PAD children, and the prognosis mainly depends on the primary disease.

Key words: Polio, Oral poliovirus vaccine, Immunodeficiency disease, Vaccine associated paralytic poliomyelitis, Acute flaccid paralysis