Flare with scleroderma; Exhaustion; Struggling with reaction to Reclast IV treatment and then second COVID shot; Struggling with reaction to Reclast IV treatment and then second COVID shot; Fever; This is a spontaneous report based on the information received by Pfizer from United Therapeutics. (Mfr Report #: UNT-2021-005514). A contactable 59-year-old female consumer (patient) received BNT162B2 (Pfizer-Biontech Covid-19 Vaccine) intramuscularly, at single dose, on an unspecified date, for COVID-19 immunisation. The patient also started to receive treprostinil sodium (TYVASO, inhalation gas) 0.6 mg/ml, from 01Jul2012 and ongoing, for pulmonary arterial hypertension and zoledronic acid (RECLAST) intravenous, from 25Mar2021 to an unspecified date, for an unknown indication. Relevant medical history included pulmonary arterial hypertension and scleroderma, both from an unspecified date and ongoing. Concomitant medications were unknown. The patient experienced flare with scleroderma, fever, exhaustion, drug hypersensitivity and vaccination adverse reaction (described as "struggling with reaction to RECLAST IV treatment and then second COVID shot").  Patient's clinical course was the following: this 59 year old female patient began therapy with IH TYVASO (treprostinil sodium, concentration of 0.6 mg/ml) delivered by Tyvaso Inhalation Device (TD-300/A) (Device only), at an unknown dose and frequency via inhalation (IH) route, on 01Jul2012 for pulmonary arterial hypertension (PAH). On 25Mar2021, the patient experienced the event of fever (pyrexia). Co-suspect medication included RECLAST (zoledronic acid). Relevant medical history included pulmonary arterial hypertension (PAH). On 25Mar2021, 8 years 8 months 25 days after initiating IH treprostinil sodium (TYVASO), the patient had an intravenous (IV) zoledronic acid (RECLAST) at afternoon and have had a fever for last three days. The reporter did not provide causality for the event of pyrexia. On an unreported date, the patient experienced the event terms of flare with scleroderma (scleroderma, medically significant), exhausted (fatigue), and struggling with reaction to RECLAST IV treatment and then second COVID shot (drug hypersensitivity and vaccination complication). Co-suspect medication included Covid-19 vaccine. The patient was still exhausted and was going back to the physician. The patient asked whether she could skip this time as she did not want to delay their schedule. The patient thought that she was just going through a flare with scleroderma. She would see her physician and GI physician in next few days. There were no associated breathing problems or airways issues. It was unknown if the patient had a history of allergy to food, medications, insect bites, latex, etc. Action taken with the IH TYVASO dose was not changed due to the events of scleroderma, pyrexia, fatigue, drug hypersensitivity, and vaccination complication and the action taken with RECLAST was not reported for the events of scleroderma, fatigue, drug hypersensitivity, and vaccination complication. At the time of reporting, the outcome of scleroderma, pyrexia, exhaustion, drug hypersensitivity, and vaccination complication was not resolved. The event, scleroderma, was assessed as serious (Important Medical Events). The reporter did not provide causality for the events of scleroderma, exhaustion, drug hypersensitivity, and vaccination complication.  Case Comment/Senders Comment: The company has assessed the serious adverse event of scleroderma as not related to IH treprostinil and TD-300/A device. Scleroderma was likely an underlying medical condition in this patient and flare ups are common in scleroderma which was the likely cause for the reported event.  No follow-up attempts are possible, information about lot number cannot be obtained.