This spontaneous case was reported by a consumer and describes the occurrence of ANAPHYLACTIC SHOCK (Anaphylactic shock), ANAPHYLACTIC SHOCK (last episode he had was on July 31) and IMMUNODEFICIENCY (immunocompromised for booster dose) in a 25-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 006a21a and 001a21a) for COVID-19 prophylaxis. No Medical History information was reported. On 26-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 26-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In January 2022, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In February 2022, the patient experienced ANAPHYLACTIC SHOCK (Anaphylactic shock) (seriousness criterion medically significant). On 31-Jul-2022, the patient experienced ANAPHYLACTIC SHOCK (last episode he had was on July 31) (seriousness criterion medically significant). On an unknown date, the patient experienced IMMUNODEFICIENCY (immunocompromised for booster dose.) (seriousness criterion medically significant). At the time of the report, ANAPHYLACTIC SHOCK (Anaphylactic shock), ANAPHYLACTIC SHOCK (last episode he had was on July 31) and IMMUNODEFICIENCY (immunocompromised for booster dose.) had not resolved. For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments. Concomitant product was not provided by the reporter. Other episode of anaphylactic shock occurred when he got the booster in Jan 2022, one month later, last episode he had was on July 31. Patient was rush to the hospital, received EpiPen, steroids, and oxygen. Company Comment: This spontaneous case concerns a 25-year-old, male patient with past drug history of administration of two doses of the mRNA-1273 vaccine (primary vaccine series), who experienced the unexpected, serious (medically significant) events of anaphylactic shock (two episodes) and immunodeficiency. The event anaphylactic shock (first episode) occurred 1 month after receiving the booster dose (third dose in the COVID-19 vaccination series) of the mRNA-1273 vaccine. The event anaphylactic shock (second episode) occurred approximately 6 months after receiving the booster dose (third dose in the COVID-19 vaccination series) of the mRNA-1273 vaccine. The start date of the event immunodeficiency was not provided. It was reported that 1 month after receiving the second dose of the mRNA-1273 vaccine, the patient experienced four episodes of anaphylactic shock. The patient sought consultation at the Emergency department four times. Details regarding the physician's assessment, laboratory test/s and treatment were not provided. It was also reported that the patient experienced another episode 6 months later. No further details were provided until 1 month after receiving the booster dose of the mRNA-1273 vaccine, the patient again experienced anaphylactic shock. No further details were provided until 2 days prior to the report when the patient had the last (recent) episode. The reporter stated that each episode 'gets worst and worst'. It was also reported that the patient is now immunocompromised. Treatment information was not provided. The events had not resolved at the time of the report. The history of administration of two doses of the mRNA-1273 vaccine remains a confounder. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report. This case was linked to MOD-2022-617185 (Patient Link). Sender's Comments: This spontaneous case concerns a 25-year-old, male patient with past drug history of administration of two doses of the mRNA-1273 vaccine (primary vaccine series), who experienced the unexpected, serious (medically significant) events of anaphylactic shock (two episodes) and immunodeficiency. The event anaphylactic shock (first episode) occurred 1 month after receiving the booster dose (third dose in the COVID-19 vaccination series) of the mRNA-1273 vaccine. The event anaphylactic shock (second episode) occurred approximately 6 months after receiving the booster dose (third dose in the COVID-19 vaccination series) of the mRNA-1273 vaccine. The start date of the event immunodeficiency was not provided. It was reported that 1 month after receiving the second dose of the mRNA-1273 vaccine, the patient experienced four episodes of anaphylactic shock. The patient sought consultation at the Emergency department four times. Details regarding the physician's assessment, laboratory test/s and treatment were not provided. It was also reported that the patient experienced another episode 6 months later. No further details were provided until 1 month after receiving the booster dose of the mRNA-1273 vaccine, the patient again experienced anaphylactic shock. No further details were provided until 2 days prior to the report when the patient had the last (recent) episode. The reporter stated that each episode 'gets worst and worst'. It was also reported that the patient is now immunocompromised. Treatment information was not provided. The events had not resolved at the time of the report. The history of administration of two doses of the mRNA-1273 vaccine remains a confounder. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.