received the diagnosis of microscopic colitis; not receiving 3rd dose while being immunocompromised; This spontaneous case was reported by a consumer and describes the occurrence of COLITIS MICROSCOPIC (received the diagnosis of microscopic colitis) in a 70-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 027121a, 011a21a, 021b21a and 004c21a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Immunocompromised, Asthma (has asthma "for almost all her life"), Thyroid disorder and Skin disorder.   On 07-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 09-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 11-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 07-Apr-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 11-Nov-2021, the patient experienced INCORRECT DOSE ADMINISTERED (not receiving 3rd dose while being immunocompromised). In February 2022, the patient experienced COLITIS MICROSCOPIC (received the diagnosis of microscopic colitis) (seriousness criterion medically significant). The patient was treated with BUDESONIDE for Colitis collagenous, at an unspecified dose and frequency. At the time of the report, COLITIS MICROSCOPIC (received the diagnosis of microscopic colitis) and INCORRECT DOSE ADMINISTERED (not receiving 3rd dose while being immunocompromised) outcome was unknown.            No concomitant medication information provided.  Company comment: This is a spontaneous case concerning a 70 year-old, female patient with a history of Thyroid disorder, who experienced the serious (due to medically important condition) unexpected, event of Colitis microscopic, approximately 3 months after the booster dose of mRNA-1273 vaccine. The patient reported treatment with budesonide for Colitis collagenous. The outcome of the event was reported not reported. The mentioned medical history remains as a risk factor for the event. Additionally, Incorrect dose administered was reported in the case since the patient received a booster dose instead of a full third dose while being immunocompromised. No further clinical information was available for medical review. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This is a spontaneous case concerning a 70 year-old, female patient with a history of Thyroid disorder, who experienced the serious (due to medically important condition) unexpected, event of Colitis microscopic, approximately 3 months after the booster dose of mRNA-1273 vaccine. The patient reported treatment with budesonide for Colitis collagenous. The outcome of the event was reported not reported. The mentioned medical history remains as a risk factor for the event. Additionally, Incorrect dose administered was reported in the case since the patient received a booster dose instead of a full third dose while being immunocompromised. No further clinical information was available for medical review. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.