Inclusion Criteria:
* History of either Definite or Highly Probable Past Lyme disease diagnosed and treated by a health care provider more than 6 months previously.
* Have one or more current symptoms attributed to Lyme disease that were also present during the initial 6-month period after diagnosis and antibiotic treatment of Lyme disease.
* Individuals reporting that current symptoms cause clinically significant distress or impairment in functioning.
* Previously treated for Lyme disease with at least two courses of antibiotics considered appropriate for Lyme disease.
* Individuals who agree to not start a new medical or psychiatric treatment (that might impact study outcomes) for their chronic symptoms during the course of this study (unless deemed necessary by their primary care physician (PCP)).
* Individuals whose current treatment (that might impact study outcomes) has been stable for at least 6 weeks prior to baseline visit.
* Lives in the U.S. and owns a smartphone, tablet or computer with Internet access.
* Able to read and understand English to be able to provide informed consent.
* Able and willing to come to Columbia University Irving Medical Center in NYC for 3-5 study visits.
* Willingness to have a 12-lead electrocardiogram (EKG) when evaluated on site and, if an EKG was conducted in the past year, willingness to try to obtain that EKG for us to review.
* Current moderate to severe fatigue. At least moderate intensity at study screening (a score of 4 or more on the Fatigue Severity Scale (FSS)).
* Ability to allocate sufficient time for the treatment sessions, including 6 sessions that will be monitored during work hours (8 am to 6 pm).
Exclusion Criteria:
* Current or past history of cardiovascular disorder(s) (coronary artery disease, peripheral artery disease, stroke, aortic disease, or other major cardiac condition). A history within the last year of unexplained fainting spells or of vasovagal syncope or feeling faint in response to medical settings or pain. Symptomatic bradycardia, orthostatic (postural) hypotension not correctable by fluid intake (i.e., a drop of \>20 mm Hg systolic, 10 mm Hg diastolic or both), or persistent hypotension (BP below 90 mmHg systolic).
* Abnormal EKG findings (e.g., significant bradycardia) considered significant by a cardiologist.
* A diagnosed current major central nervous system disease (e.g., multiple sclerosis (MS), epilepsy, neurodegenerative diseases, ischemic stroke, Parkinson's, traumatic brain injury with cognitive impairment, etc.) or a history of brain surgery or brain tumors.
* A current psychiatric disorder that might impact treatment compliance (e.g., bipolar disorder, psychosis, substance abuse).
* Suicidal ideation with method, plan or intent in the last 6 months or a lifetime history of suicidal behavior.
* Current moderate-severe or severe depression (T-score of 65 or higher on the PROMIS-Emotional Distress-Depression SF) at screening.
* Current serious unstable medical illness.
* Currently taking opiate-based medication or have taken antibiotics in the last 6 weeks for tick-borne illness.
* Ear-related: a) facial or ear pain; b) recent ear trauma; c) damage to left or right ear or anatomy that does not allow taVNS; d) ear infection (otitis media or externa); e) scar or inflammation on ear; f) Cochlear implants.
* Currently or recently (within 6 months) in a clinical trial of an investigational medicinal product or another medical device.
* Females who are pregnant or planning to become pregnant during the course of this study.
* Unable to connect to the Internet during treatment phase.
* Individuals with an active external or implanted electrical medical device (e.g., cardiac pacemaker, hearing aid implant) or any metal implant above the level of the neck.
* Individuals who have had surgery to cut the vagus nerve in the neck (cervical vagotomy).
