My lymph nodes were swollen under both armpits; patient is immunocompromised and received the 3rd dose of mRNA-1273 vaccine (Monovalent) more than a month as per the recommended schedule and was given a booster dose vs the primary 3rd dose; This spontaneous case was reported by a patient and describes the occurrence of LYMPHADENOPATHY (My lymph nodes were swollen under both armpits) in a 64-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     Family history included Leukemia (Blood cancer runs in patient's family). Concurrent medical conditions included Immunocompromised and Thalassemia.   On 31-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 28-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 06-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 06-Nov-2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (patient is immunocompromised and received the 3rd dose of mRNA-1273 vaccine (Monovalent) more than a month as per the recommended schedule and was given a booster dose vs the primary 3rd dose). On 07-Nov-2021, the patient experienced LYMPHADENOPATHY (My lymph nodes were swollen under both armpits) (seriousness criterion hospitalization). At the time of the report, LYMPHADENOPATHY (My lymph nodes were swollen under both armpits) had not resolved and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (patient is immunocompromised and received the 3rd dose of mRNA-1273 vaccine (Monovalent) more than a month as per the recommended schedule and was given a booster dose vs the primary 3rd dose) outcome was unknown.            No concomitant medications were reported.  The patient reported that her symptoms had worsened.  Her doctor had done all kinds of test and blood work and said patient was fine. The patient reported that AE caused her to seek medical care (office visit, Urgent care, ER, hospitalized).  No treatment information was reported.  Company Comment: This is a spontaneous case concerning a 64-year-old female patient with relevant medical history of Immunocompromised, who experienced the unexpected, serious, event of Lymphadenopathy which led to the hospitalization of the patient and occurred 1 day after receiving the third dose of mRNA-1273 Vaccine. No further information on risk factors, co morbidities, clinical course and management of the events was available in the report. Additionally, Inappropriate Schedule of Product Administration was reported as the patient is immunocompromised and received the 3rd dose of mRNA-1273 vaccine (Monovalent) more than a month as per the recommended schedule. The reported outcome of the event Lymphadenopathy has not resolved. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.   This case was linked to MOD-2022-647023, MOD-2022-647026 (Patient Link).; Sender's Comments: This is a spontaneous case concerning a 64-year-old female patient with relevant medical history of Immunocompromised, who experienced the unexpected, serious, event of Lymphadenopathy which led to the hospitalization of the patient and occurred 1 day after receiving the third dose of mRNA-1273 Vaccine. No further information on risk factors, co morbidities, clinical course and management of the events was available in the report. Additionally, Inappropriate Schedule of Product Administration was reported as the patient is immunocompromised and received the 3rd dose of mRNA-1273 vaccine (Monovalent) more than a month as per the recommended schedule. The reported outcome of the event Lymphadenopathy has not resolved. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.