Lung collapse; Diaphragm paralysis; breathing issues due to paralysis in diaphragm and collapsed lung/breathing issues worsening; COVID-19 vaccine slowed him down somewhat after the vaccine/slowed him down somewhat; This solicited report from a consumer (wife of the patient) as part of a regulatory authority via an affiliate. An elderly male patient received second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, lot number and expiry dates were not provided) via an unspecified route of administration, on 12Mar2021 as a single dose for COVID-19 immunization. Medical history included Thymectomy on 25Jul2019, ongoing myasthenia gravis. Concomitant medications included eculizumab (ECULIZUMAB, concentrate for solution, strength: 300 mg), from 30Sep2019, at 10 mg for Myasthenia gravis. The most recent dose of Soliris was not reported. Historical vaccine included first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, lot number and expiry dates were not provided) via an unspecified route of administration, on an unknown date, as a single dose for COVID-19 immunization; meningococcal vaccine a/c/y/w conj (CRM197) (MENVEO) on 17Sep2018 for immunisation; meningococcal vaccine b rfhbp/nada/nhba omv (BEXSERO) on 13Sep2019 for immunisation and patient was administered with an unknown vaccine on 23Sep2019. On an unspecified date, the patient was still experiencing breathing issues due to paralysis in diaphragm and collapsed lung. According to the wife of the patient, soliris began to wear out right before they do it again. It was reported that patient was doing well on treatment. On an unspecified date, breathing issues of the patient was progressively worsening. The patient stated that COVID-19 vaccine slowed him down somewhat after the vaccine/slowed him down somewhat. No additional clinical details were reported. No other laboratory or diagnostic tests were reported. Treatment for the events was not reported.  The patient had a follow-up with pulmonary provider and had testing ordered but was cancelled due to COVID-19 outreach, and tests need to be rescheduled. The patient continues to be followed by pulmonologist and neurologist. Outcome of the events diaphragm paralysis, breathing issues, and lung collapse was not resolved for other event it was unknown.   The reporter provided a causality assessment of related for the event slowed him down somewhat in relation to COVID-19 vaccine Pfizer and not reported for remaining event. Since no determination has been received, the case is managed based on the company causality. No other possible etiological factors were reported.  Company Comment : Upon follow up this case is a serious, not medically confirmed, solicited report of diaphragmatic paralysis (MS) and pneumothorax (MS). Non-serious event of therapeutic product effect decreased, dyspnoea, and ill-defined disorder were also reported. Only dyspnoea is listed in the publication among the reported events. The company considers the events not related to Soliris. Relevant medical information is limited and the report does not include the cause and/or the circumstances that led to the events, ill-defined disorder not related to Soliris. The causality for the events is unknown for the Covid-19 vaccine.   No follow-up attempts are needed. No further information is expected.; Sender's Comments: The events diaphragmatic paralysis, dyspnoea and pneumothorax are due to the respiratory complications of Myasthenia gravis and not related to BNT162B2 but the association between the event Ill-defined disorder and BNT162B2 cannot be completely ruled out.