SARS-CoV-2 vaccinations can lead to complications, including post-acute COVID-19 vaccination syndrome (PACVS). There has been no report of a patient with PACVS presenting with Guillain-Barre syndrome (GBS), myocarditis/pericarditis, immunodeficiency, or coagulopathy after the second BNT162b2 dose. The patient is a 51-year-old woman with chronic myopericarditis, coagulopathy due to factor-VIII increase and protein-S deficiency, GBS, and a number of other ocular, dermatological, immunological, and central nervous system abnormalities related to the second dose of the BNT172b2 vaccine. GBS manifested with mild, multiple cranial nerve lesions, small fibre neuropathy (SFN) affecting the autonomic system with postural tachycardia syndrome (POTS) and orthostatic hypotension, and sensory disturbances in the upper and lower limbs. PACVS was diagnosed months after onset, but despite the delayed diagnosis, the patient benefited from glucocorticoids, repeated HELP apheresis, and multiple symptomatic treatments. The case shows that SARS-CoV-2 vaccination can be complicated by PACVS manifesting as chronic myopericarditis, coagulopathy, GBS with predominant dysautonomia, and impaired immune competence, and that diagnosis of PACVS can be delayed for months. Delayed diagnosis of PACVS may result in a delay in appropriate treatment and the prolongation of disabling symptoms. Patients and physicians should be made aware of PACVS to improve diagnostic and therapeutic management in terms of patient and healthcare system costs.