A severe presentation of breakthrough infection caused by the Omicron variant with radiological findings of COVID-19 pneumonia in an elderly woman.

Omicron variant of COVID-19 is characterized by exceptional transmissibility and by immune evasion with the ability infect people with naturally acquired or vaccine-induced immunity. However, lung involvement is poorly reported in patients who resulted positive by this new COVID-19 variant. COVID-19 breakthrough infections are defined as COVID-19 infection in fully vaccinated patients. Herein, we present a case of breakthrough infection in an elderly woman who came in emergency with dyspnea and with findings of COVID-19 pneumonia on chest computed tomography. The patient was vaccinated with a booster dose of an mRNA vaccine some months earlier and the Omicron variant was detected on real-time reverse-transcription polymerase chain reaction. However, the patient's condition remained stable. For our knowledge we report the first case with lung involvement due to Omicron variant in an elderly after the booster dose of mRNA vaccine. This case highlights as COVID-19 breakthrough infections may represent some concerns in the elderly patients in presence of virus variants.