POTS co-morbid with CFS. It turns out that several vaccines that have a ‘vaccine syndrome’ which included POTS.
- Orthostatic intolerance and postural tachycardia syndrome as suspected adverse effects of vaccination against human papilloma virus .
- [Neurologic Complications in HPV Vaccination] . “delayed manifestation of cognitive dysfunction in the post-vaccinated girls has attracted attention. The symptoms include memory loss and difficulty in reading textbooks and/or calculation.”
- Postural tachycardia syndrome after vaccination with Gardasil.
- Paroxysmal supraventricular tachycardia precipitated by pertussis vaccine .
- [Associated ventricular tachycardia and auricular fibrillation after anticholera vaccination].
- [Neurological complications after influenza vaccination (author’s transl)]. 
- Neurological complications of swine influenza vaccination. 
This is not that surprising, because the vaccine promotes an immune response which likely includes alteration of the microbiome.
“..a trend for reduced gamma-interferon in the CFS-vaccine group… Polio vaccination was not found to be clinically contraindicated in CFS patients, however, there was evidence of altered immune reactivity and virus clearance.” 
The following illustrates how adverse effects are often deem “not significant” in a population .
VAERS received 294 reports of AEs in pregnant women who received 2009-H1N1 vaccine: 288 after inactivated and 6 after the live attenuated vaccines. Two maternal deaths were reported. Fifty-nine women (20.1%) were hospitalized. We verified 131 pregnancy-specific outcomes: 95 spontaneous abortions (<20 weeks); 18 stillbirths (≥20 weeks); 7 preterm deliveries (<37 weeks); 3 threatened abortions; 2 preterm labor; 2 preeclampsia; and 1 each of fetal hydronephrosis, fetal tachycardia, intrauterine growth retardation, and cleft lip.
Review of reports to VAERS following H1N1 vaccination in pregnant women did not identify any concerning patterns of maternal or fetal outcomes.”