different behavior that was unlike anything he has ever done; anxious, scared; Sad; having delusions; not sleeping; taking a long time to eat; lost 4 pounds; hallucinating\talking to someone in his room that wasn't there/hearing voices of people talking to him; boil type infection near armpit; This spontaneous case was reported by a consumer and describes the occurrence of HALLUCINATION (hallucinating\talking to someone in his room that wasn't there/hearing voices of people talking to him) in a 31-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 032M20A and 038B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Down's syndrome.   On 05-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 14-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 01-Apr-2021, the patient experienced INFECTION (boil type infection near armpit). On an unknown date, the patient experienced HALLUCINATION (hallucinating\talking to someone in his room that wasn't there/hearing voices of people talking to him) (seriousness criterion medically significant), ABNORMAL BEHAVIOUR (different behavior that was unlike anything he has ever done), ANXIETY (anxious, scared), DEPRESSED MOOD (Sad), DELUSION (having delusions), INSOMNIA (not sleeping), EATING DISORDER (taking a long time to eat) and WEIGHT DECREASED (lost 4 pounds). At the time of the report, HALLUCINATION (hallucinating\talking to someone in his room that wasn't there/hearing voices of people talking to him), INFECTION (boil type infection near armpit), ABNORMAL BEHAVIOUR (different behavior that was unlike anything he has ever done), ANXIETY (anxious, scared), DEPRESSED MOOD (Sad), DELUSION (having delusions), INSOMNIA (not sleeping), EATING DISORDER (taking a long time to eat) and WEIGHT DECREASED (lost 4 pounds) outcome was unknown.            On 01Apr2021, he had a boil type infection near his armpit. She wasn't able to get an appointment for the doctor until two days after so in the meantime she put hot compresses which helped. The MD prescribed an antibiotic that helped and it went away. Last Thursday, maybe seven or eight days later, her son showed different behavior that was unlike anything he has ever done. He was hallucinating and talking to someone in his room that wasn't there, he was anxious, sad, scared, and having delusions and hearing voices of people talking to him. He is normally self sufficient but he went from his normal routine and she had to tell him to eat and brush his teeth which he would normally do on his own. He is also not sleeping, taking a long time to eat which is unlike him, and has lost 4 pounds. His second dose (lot# 038B21A) was yesterday 14Apr2021. She is concerned if it is related to the vaccine or the antibiotic.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.