J Korean Med Sci.  2023 Apr;38(14):e106. 10.3346/jkms.2023.38.e106.

COVID-19 Vaccine-Associated Pneumonitis in the Republic of Korea: A Nationwide Multicenter Survey

  • 1Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
  • 2Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
  • 3Division of Allergy, Pulmonary and Critical Care Medicine, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea
  • 4Division of Allergy and Respiratory Medicine, Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea
  • 5Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, School of Medicine, Inha University, Incheon, Korea
  • 6Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, Busan Paik Hospital, Inje University, Busan, Korea
  • 7Division of Pulmonary, Department of Internal Medicine, College of Medicine, Wonkwang University, Iksan, Korea
  • 8Division of Pulmonary and Critical Medicine, Department of Internal Medicine, Ulsan University Hospital, College of Medicine, University of Ulsan, Ulsan, Korea
  • 9Department of Internal Medicine, Gyeongsang National University Hospital, Jinju, Korea
  • 10Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
  • 11Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
  • 12Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea
  • 13Division of Respiratory-Allergy and Clinical Immunology, Department of Internal Medicine, Konkuk University Medical Center, Seoul, Korea
  • 14Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
  • 15Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
  • 16Department of Internal Medicine, Myongji Hospital, Hanyang University College of Medicine, Goyang, Korea
  • 17Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kyunghee University Hospital, Seoul, Korea


Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2.
In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies.
From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26. COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients.
These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.


COVID-19; Interstitial Lung Disease; Pneumonitis; SARS-CoV-2; Vaccine


  • Fig. 1 Chest high-resolution computed tomography and histopathology of vaccine-associated interstitial lung disease in a 56-year-old female patient who received the first dose of BNT162b COVID-19 vaccine. Axial (panel A and B) high-resolution CT images show bilateral patch consolidation along bronchovascular bundles in lower lung zones and ground-glass opacities in upper lung zones. Lung specimen (panel C, H&E stain, ×1 original magnification) obtained by surgical biopsy. Lower power magnification (panel E and D, H&E stain, ×15 magnification) demonstrates multiple fibroblastic plugs in alveolar sacs (organizing pneumonia pattern) and uniform interstitial inflammation and thickening with lymphocytes (cellular nonspecific interstitial pneumonia pattern). High-magnification (panel F, H&E stain, ×100 magnification) shows lymphocyte infiltration in interstitium.


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