COVID-19 mRNA Vaccine-induced Pneumonitis

A 65-year-old man experienced cough and shortness of breath 3 days after receiving the first dose of the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine. Chest X-ray revealed bilateral infiltrates, and the desaturation deteriorated rapidly. The symptoms and radiographic abnormalities rapidly improved after the initiation of corticosteroid therapy. Intradermal testing of the Pfizer-BioNTech COVID-19 vaccine showed a delayed positive reaction. Based on these findings, the patient was diagnosed with COVID-19 vaccine-induced pneumonitis. The timing of the onset of pneumonitis after vaccination and the results of intradermal testing suggest that Type IV hypersensitivity against COVID-19 vaccine may have been responsible for this clinical condition.