Dyspnea; Cough; Acute hypoxemic respiratory failure; worsening of bilateral infiltrates; clinical condition deteriorated; Cryptogenic organizing pneumonia; This case was reported in a literature article and described the occurrence of cryptogenic organizing pneumonia in a 65-year-old male patient who received Flu Seasonal QIV Quebec (FluLaval Quadrivalent) for prophylaxis.   On an unknown date, the patient received FluLaval Quadrivalent at an unknown dose. On an unknown date, less than a month after receiving FluLaval Quadrivalent, the patient experienced cryptogenic organizing pneumonia (serious criteria GSK medically significant), dyspnea (serious criteria hospitalization), cough (serious criteria hospitalization), acute respiratory failure (serious criteria hospitalization and GSK medically significant), bilateral pulmonary infiltrates and general physical health deterioration. The patient was treated with antibiotics nos (Antibiotics (Brand Names Not Known)), methylprednisolone sodium succinate (Solumedrol) and prednisone. On an unknown date, the outcome of the cryptogenic organizing pneumonia, dyspnea, cough, acute respiratory failure, bilateral pulmonary infiltrates and general physical health deterioration were recovered/resolved.   The reporter considered the cryptogenic organizing pneumonia, dyspnea, cough, acute respiratory failure, bilateral pulmonary infiltrates and general physical health deterioration to be related to FluLaval Quadrivalent.  Additional details were provided as follows: This case was reported in a literature article and described the cryptogenic organizing pneumonia (COP) in a male patient aged 65-year-old who was vaccinated with Flulaval quadrivalent vaccine (GlaxoSmithKline) for prophylaxis. The patient was a male. No information on patient's medical or family history or concomitant medication or concurrent condition was provided.  On an unspecified date in 2016, the patient received Flulaval quadrivalent vaccine (administration route and site unspecified; dosage unknown; batch number not provided). The age of vaccination was not provided but it could be 64 or 65 year. The patient had no immediate adverse effects. On an unspecified date, within a month after vaccination, the patient developed the symptoms of COP. A month after vaccination, the patient was hospitalized with dyspnea and cough leading to acute hypoxemic respiratory failure. Patient was started on non-invasive ventilation and antibiotics. Patient's clinical condition deteriorated with worsening of bilateral infiltrates. Bronchoalveolar lavage showed acute inflammatory cells with cultures being negative. Right upper lobe wedge biopsy showed COP. Patient was started on intravenous (IV) Solumedrol and transitioned to high dose oral prednisone. 1 week later, the patient was clinically better. Prednisone was continued 3 months more and then discontinued. Repeat computed tomography (CT) chest with contrast showed resolution of the infiltrates. In 2017, (a year later after the initial presentation), the patient received Fluzone vaccine (inactivated quadrivalent vaccine) and had no immediate complications. Within a month after vaccination, the patient again developed symptoms of COP. One month after vaccination, the patient presented with weakness, dyspnea, fever, hemoptysis and cough. Imaging showed patchy bilateral multifocal infiltrates Infectious etiology was ruled out. Based on the similarities to patient's presentation a year ago, COP secondary to the inactivated quadrivalent vaccine was felt likely and patient was started on steroids. Chest x-ray showed improved aeration bilaterally with eventual clearing of infiltrates. This case has been considered as serious due to hospitalization.  The author commented "The patient had biopsy proven COP in the first instance. A year later, the temporal relationship to the influenza vaccination, the similar clinical picture, absence of infection and the response to steroids made this presumptively COP. Both instances were within 1 month of receiving an inactivated quadrivalent flu vaccine. Despite this possible complication, Influenza vaccine is necessary to prevent morbidity and mortality in susceptible individuals".  The authors concluded "We present this rare complication of influenza vaccination to increase clinician awareness of this condition. COP due to influenza vaccination can be serious; however, early intervention and diagnosis can be key to preventing further complications. Despite this possible complication, Influenza vaccine is necessary to prevent morbidity and mortality in susceptible individuals."  This article is not available for regulatory submission due to copyright restriction.      Lab Comments: On an unspecified date, lab test were done. Bronchoalveolar lavage showed acute inflammatory cells with cultures being negative. Right upper lobe wedge biopsy showed Cryptogenic organizing pneumonia. Repeat computed tomography (CT) chest with contrast showed resolution of the infiltrates.