Immunocompromised/LIMITED ANTIBODY RESPONSE TO JANSSEN COVID-19 VACCINE AND MODERNA COVID-19 VACCINE; Diarrhea; interchange of vaccine products; revaccination with different COVID-19 vaccine; This spontaneous case was reported by a consumer and describes the occurrence of IMMUNODEFICIENCY (Immunocompromised/LIMITED ANTIBODY RESPONSE TO JANSSEN COVID-19 VACCINE AND MODERNA COVID-19 VACCINE) in an elderly patient of an unknown gender who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Co-suspect products included non-company products COVID-19 VACCINE NRVV AD26 (JNJ 78436735) (JANSSEN COVID-19 VACCINE) for COVID-19 vaccination and IBRUTINIB (IMBRUVICA) capsule for Waldenstrom's macroglobulinemia.    Concurrent medical conditions included Waldenstrom's macroglobulinaemia. Concomitant products included ZANUBRUTINIB for an unknown indication.   In April 2021, the patient received first dose of COVID-19 VACCINE NRVV AD26 (JNJ 78436735) (JANSSEN COVID-19 VACCINE) (Intramuscular) 1 dosage form. On an unknown date, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form and IBRUTINIB (IMBRUVICA) (Oral) (Capsule)(IBRUTINIB). On an unknown date, the patient experienced IMMUNODEFICIENCY (Immunocompromised/LIMITED ANTIBODY RESPONSE TO JANSSEN COVID-19 VACCINE AND MODERNA COVID-19 VACCINE) (seriousness criterion medically significant), DIARRHOEA (Diarrhea), INTERCHANGE OF VACCINE PRODUCTS (interchange of vaccine products) and COVID-19 IMMUNISATION (revaccination with different COVID-19 vaccine). At the time of the report, IMMUNODEFICIENCY (Immunocompromised/LIMITED ANTIBODY RESPONSE TO JANSSEN COVID-19 VACCINE AND MODERNA COVID-19 VACCINE), DIARRHOEA (Diarrhea), INTERCHANGE OF VACCINE PRODUCTS (interchange of vaccine products) and COVID-19 IMMUNISATION (revaccination with different COVID-19 vaccine) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, SARS-CoV-2 antibody test: (Positive) Positive.         The patient has other concomitant therapy of Bruton Tyrosine Kinase inhibitors. It was unknown whether patient was enrolled in a COVID-19 Vaccine Trial. The reporter causality for the events of immunocompromised, COVID-19, Diarrhea was Not Reported for cosuspect imbruvica. The reporter causality for the events of immunocompromised, COVID-19, Diarrhea was Not Reported for cosuspect Janssen COVID-19 vaccine. No treatment medications were reported. This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.  Company comment: This spontaneous case concerns an elderly patient of unknown gender and age with medical history of Waldenstrom's macroglobulinemia, who experienced the unexpected, serious (medically significant) event of immunodeficiency an unknow time after the booster dose of mRNA-1273. The medical history of Waldenstrom's macroglobulinemia and treatment with ibrutinib, as well as vaccination with Janssen COVID-19 vaccine (1st dose), could be confounding factors. Outcome was reported as unknown. The benefit-risk relationship of mRNA-1273 is not affected by this report.   Reporter did not allow further contact; Sender's Comments: This spontaneous case concerns an elderly patient of unknown gender and age with medical history of Waldenstrom's macroglobulinemia, who experienced the unexpected, serious (medically significant) event of immunodeficiency an unknow time after the booster dose of mRNA-1273. The medical history of Waldenstrom's macroglobulinemia and treatment with ibrutinib, as well as vaccination with Janssen COVID-19 vaccine (1st dose), could be confounding factors. Outcome was reported as unknown. The benefit-risk relationship of mRNA-1273 is not affected by this report.