"weird things gone on"; never got the second Moderna shot; hives; swollen lip; swollen tongue, back to the emergency room; severe allergic reaction; cellulitis in her left thigh; "big abscess" on her groin; lump in her groin area; looked like a red bump; looked like a swollen lymph node, she squeezed it, but nothing came out; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of CELLULITIS (cellulitis in her left thigh), HYPERSENSITIVITY (severe allergic reaction), INGUINAL MASS (lump in her groin area), ERYTHEMA (looked like a red bump), ABSCESS ("big abscess" on her groin), FEELING ABNORMAL ("weird things gone on"), URTICARIA (hives), LIP SWELLING (swollen lip), SWOLLEN TONGUE (swollen tongue, back to the emergency room), LYMPHADENOPATHY (looked like a swollen lymph node, she squeezed it, but nothing came out) and PRODUCT DOSE OMISSION ISSUE (never got the second Moderna shot) in a 60-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 003B21A) for COVID-19 vaccination.     The patient's past medical history included Breast cancer (diagnosed with breast cancer 6 years ago. She stated she has been in breast cancer remission for 5 years.), Lumpectomy and Radiation therapy. Previously administered products included for Product used for unknown indication: Tdap booster and Flu vaccine (she has had reactions and severe symptoms). Past adverse reactions to the above products included Reaction allergic (NOS) with Flu vaccine and Tdap booster. Concurrent medical conditions included Allergy to antibiotic (Keflex).    On 26-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-Mar-2021, the patient experienced INGUINAL MASS (lump in her groin area) (seriousness criteria hospitalization and medically significant), ERYTHEMA (looked like a red bump) (seriousness criteria hospitalization and medically significant) and LYMPHADENOPATHY (looked like a swollen lymph node, she squeezed it, but nothing came out) (seriousness criteria hospitalization and medically significant). On 28-Mar-2021, the patient experienced CELLULITIS (cellulitis in her left thigh) (seriousness criteria hospitalization and medically significant) and ABSCESS ("big abscess" on her groin) (seriousness criteria hospitalization and medically significant). On 12-Apr-2021, the patient experienced HYPERSENSITIVITY (severe allergic reaction) (seriousness criteria hospitalization and medically significant), URTICARIA (hives) (seriousness criteria hospitalization and medically significant), LIP SWELLING (swollen lip) (seriousness criteria hospitalization and medically significant) and SWOLLEN TONGUE (swollen tongue, back to the emergency room) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced FEELING ABNORMAL ("weird things gone on") (seriousness criteria hospitalization and medically significant) and PRODUCT DOSE OMISSION ISSUE (never got the second Moderna shot) (seriousness criteria hospitalization and medically significant). The patient was hospitalized from 28-Mar-2021 to 01-Apr-2021 due to ABSCESS, CELLULITIS, ERYTHEMA, FEELING ABNORMAL, HYPERSENSITIVITY, INGUINAL MASS, LIP SWELLING, LYMPHADENOPATHY, PRODUCT DOSE OMISSION ISSUE, SWOLLEN TONGUE and URTICARIA. The patient was treated with VANCOMYCIN from 28-Mar-2021 to 01-Apr-2021 for Adverse event, at an unspecified dose and frequency; CIPROFLOXACIN (CIPRO [CIPROFLOXACIN]) from 01-Apr-2021 to 10-Apr-2021 for Adverse event, at an unspecified dose and frequency; CLINDAMYCIN from 01-Apr-2021 to 10-Apr-2021 for Adverse event, at an unspecified dose and frequency and Surgery (drainage surgery of the abscess) for Abscess. At the time of the report, CELLULITIS (cellulitis in her left thigh), HYPERSENSITIVITY (severe allergic reaction), INGUINAL MASS (lump in her groin area), ERYTHEMA (looked like a red bump), ABSCESS ("big abscess" on her groin), FEELING ABNORMAL ("weird things gone on"), URTICARIA (hives), LIP SWELLING (swollen lip), SWOLLEN TONGUE (swollen tongue, back to the emergency room), LYMPHADENOPATHY (looked like a swollen lymph node, she squeezed it, but nothing came out) and PRODUCT DOSE OMISSION ISSUE (never got the second Moderna shot) outcome was unknown.        mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was withdrawn on an unknown date.       Patient stated that she had to have a home health nurse help her do dressing changes for 12 days in her home after being discharged. On 12APR2021, she had a severe allergic reaction, hives, swollen lip and tongue. She stated that she had to go back to the emergency room for the severe allergic reaction. The caller mentioned that she asked her healthcare provider if she should get the second Moderna vaccine and he advised her not to get the vaccine or she could end up on a ventilator. The caller stated that she travels for work and is now housebound because she hasn't received the second dose in the series.  She stated since she can't leave the house because she is not fully vaccinated, and it is affecting her ability to earn a living, as her job requires her to travel.  Company Comment: This report refers to a case of product dose omission, with associated AEs. 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.  No further information is expected.; Sender's Comments: This report refers to a case of product dose omission, with associated AEs. 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.  No further information is expected.