ObjectiveTo describe the imaging and clinical features of vaccinia virus induced pneumonia by long-term follow-up.MethodsThe clinical data, imaging features and long-term follow-up of 5 patients with vaccinia virus pneumonia admitted to Wuxi People's Hospital Affiliated to Nanjing Medical University were analyzed.ResultsAll the 5 patients were male, aged between 21 and 54 years. The latent period of the disease was 2 to 5 days. All the patients had fever and pneumonia, while 3 of them had herpes. Two patients with severe pneumonia showed extensive patchy and nodular shadows in both lungs. Chest CT findings of the other three patients showed scattered small nodules in both lungs. All patients were followed up by telephone every half a year for 3 years. The prognosis of all patients was good. The patients reported in the English literature were clinically clustered, with fever, vomiting and rash as the main symptoms.ConclusionsVaccinia virus may cause different clinical symptoms through different transmission routes, and its infectivity is strong. Biological protection should be strengthened in laboratory and working environment.