This case was reported in a literature article and described the occurrence of acute interstitial pneumonitis in a 37-year-old male patient who received dTpa vaccine. Concurrent medical conditions included connective tissue disorder (possible connective tissue disease) and interstitial lung disease. On an unknown date, the patient received dTpa vaccine at an unknown dose. On an unknown date, less than a month after receiving dTpa vaccine, the patient experienced acute interstitial pneumonitis (serious criteria hospitalization and GSK medically significant), respiratory failure (serious criteria hospitalization and GSK medically significant), diffuse alveolar damage (serious criteria hospitalization and GSK medically significant), hypoxemia (serious criteria hospitalization and GSK medically significant), connective tissue disorder (serious criteria hospitalization), atypical pneumonia (serious criteria hospitalization),  anorexia (serious criteria hospitalization), rash (serious criteria hospitalization), weight loss (serious criteria hospitalization) dyspnea (serious criteria hospitalization), condition aggravated (serious criteria hospitalization), myalgia (serious criteria hospitalization), fever (serious criteria hospitalization) and fatigue (serious criteria hospitalization). The patient was treated with doxycycline, LEVAQUIN, prednisone, Supplemental Oxygen, Steroids and immunoglobulins NOS (IVIg). On an unknown date, the outcome of the acute interstitial pneumonitis, respiratory failure, diffuse alveolar damage, hypoxemia, connective tissue disorder, atypical pneumonia, anorexia, rash, weight loss, dyspnea, myalgia, fever and fatigue were recovering/resolving and the outcome of the condition aggravated was unknown. The reporter considered the acute interstitial pneumonitis, respiratory failure, diffuse alveolar damage, hypoxemia, connective tissue disorder, atypical pneumonia, anorexia, rash, weight loss, dyspnea, condition aggravated, myalgia, fever and fatigue to be related to dTpa vaccine. Additional information was provided. This case was reported in a literature article and described the occurrence of Rapidly Progressive Interstitial Lung Disease in a 37-years old male patient who was vaccinated with unspecified Tdap vaccine (manufacturer unknown). The patient may have an underlining condition of connective disease associated Interstitial Lung Disease. No information on patient's family history or concomitant medication was provided. On an unspecified date, the patient received unspecified Tdap vaccine (administration route and site unspecified; dosages unknown; batch number not provided). Age of vaccination was not provided. On an unspecified date, within few days after vaccination, the patient developed myalgias, anorexia, fatigue and rash. He was evaluated by his primary care physician and was told he had a typical post-immunization response. His symptoms progressed to fever, weight loss, and shortness of breath. A month post vaccination, the patient was presented to the emergency department (ED) and was treated for pneumonia with doxycycline for 10 days without significant improvement. A week later, he returned to the ED and was admitted for work up of possible Type 3 Hypersensitivity reaction to vaccine. His work up showed positive antinuclear antibody. Sjogren's-syndrome-related antigen A, and anti-ribonucleoprotein with elevated creatine kinase peaked at 701 U/L. Computed tomography (CT) chest at that time showed minimal basilar interstitial changes. He was started on prednisone 80 mg daily, and LEVAQUIN 500 mg daily, supplemental oxygen, and discharged home with diagnosis of Atypical pneumonia and possible connective tissue hypoxemic disease. After a week, he was admitted for worsening respiratory failure and a repeat CT of the chest revealed diffuse ground glass opacities consistent with pneumonitis. Despite treatment with high dose steroids and five days of intravenous immunoglobulin (IVIg), the patient's disease progressed. Due to lack of clinical response, he required veno-venous extracorporeal membrane oxygenation (VV ECMO) support briefly. He underwent successful bilateral lung transplantation and was doing well. Pathology from native lung explants showed acute and organizing diffuse alveolar damage. This case has been considered serious due to hospitalisation. The author stated, "The temporal relationship between vaccination and onset of pneumonitis and respiratory failure in this case cannot be ignored. This may represent the first reported cause of Tdap vaccine related acute pneumonitis. Alternatively, the patient may have had an underlying connective tissue disease associated ILD that exacerbated in the setting of up-regulation of his immune system following vaccine exposure."