Poxviridae Pneumonia

Poxviridae family includes several viruses that infecting humans usually causes skin lesions only, but in some cases their clinical course is complicated by viral pneumonia (with or without bacterial superinfections). Historically variolaVariola virus has been the poxviridae most frequently associated with the development of pneumonia with many large outbreaks worldwide before its eradication in 1980. It is still considered a biological threat for its potential in biological warfare and bioterrorism. SmallpoxSmallpox pneumonia can be severe with the onset of acute respiratory distress syndrome (ARDS) and death. VacciniaVacciniavirus, used for vaccination against smallpoxSmallpox exceptionally, in immunocompromised patients, can induce generalized (with also lung involvement) severe disease after vaccination. MPXVMPXV virus occasionally can cause pneumonia particularly in immunocompromised patients. The pathophysiology of poxviridae pneumonia is still an area of active research; however, in animal models these viruses can cause both direct damage to the lower airways epithelium and a hyperinflammatory syndrome, like a cytokine storm. Multiple mechanisms of immune evasion have also been described. The treatment of poxviridae pneumonia is mainly based on careful supportive care. Despite the absence of randomized clinical trials in patients with poxviridae pneumonia there are antiviral drugs, such as tecovirimat, cidofovir and brincidofovir, FDA-approved for use in smallpoxSmallpox and also available under an expanded access protocol for treatment of MPXVMPXV. There are 2 (replication-deficient modified vacciniaVaccinia Ankara and replication-competent vacciniaVaccinia virus) smallpoxSmallpox vaccines FDA-approved with the first one also approved for prevention of MPXVMPXV in adults that are at high risk of infection.