Was immunocompromised after 1st dose of moderna vaccine/Was not immunocompromised before 1st dose of moderna vaccine; This spontaneous case was reported by a consumer and describes the occurrence of IMMUNODEFICIENCY (Was immunocompromised after 1st dose of moderna vaccine/Was not immunocompromised before 1st dose of moderna vaccine) in a 75-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 031L20A, 025A21A and 049E21A) for COVID-19 vaccination.     No Medical History information was reported.   On 03-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 03-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 19-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient experienced IMMUNODEFICIENCY (Was immunocompromised after 1st dose of moderna vaccine/Was not immunocompromised before 1st dose of moderna vaccine) (seriousness criterion medically significant). At the time of the report, IMMUNODEFICIENCY (Was immunocompromised after 1st dose of moderna vaccine/Was not immunocompromised before 1st dose of moderna vaccine) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       The patient became immunocompromised after received the first dose of the moderna vaccine but was not in the immunocompromised category prior to receiving the 1st dose of the moderna vaccine. The caller refused to provide past medical history and stated no for concomitant medications and for treatment received. The patient did not get the booster dose but got the full 3rd dose for immunocompromised patients. The caller stated that it has been over 6 months since he got his 3rd dose of the moderna vaccine and asked if the full dose is enough to carry him for another 6 months.  No concomitant medication was reported. No treatment medication was reported.  This is a spontaneous case concerning a 75-year-old male patient with no medical history reported, who experienced the unexpected event of immunodeficiency. The event occurred on an unknown date while the third dose of mRNA  1273 vaccine was received on 19-Aug-2021. Immunodeficiency, a medically significant event had an unknown outcome still at the time of report. The rechallenge in this case is positive as the same event was experienced after the first dose. The reporter's assessment was not provided. The benefit-risk relationship of the vaccine is not affected by this report.; Sender's Comments: This is a spontaneous case concerning a 75-year-old male patient with no medical history reported, who experienced the unexpected event of immunodeficiency. The event occurred on an unknown date while the third dose of mRNA  1273 vaccine was received on 19-Aug-2021. Immunodeficiency, a medically significant event had an unknown outcome still at the time of report. The rechallenge in this case is positive as the same event was experienced after the first dose. The reporter's assessment was not provided. The benefit-risk relationship of the vaccine is not affected by this report.