Interchange of vaccine products; severely ill after booster; terrible headache that was worse than before with Pfizer; her face was numb/left hand on left hand side was numb; This spontaneous case was reported by a consumer and describes the occurrence of ILLNESS (severely ill after booster), HEADACHE (terrible headache that was worse than before with Pfizer) and HYPOAESTHESIA (her face was numb/left hand on left hand side was numb) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Previously administered products included for COVID-19 vaccination: Pfizer vaccine (received Pfizer for the first 3 primary doses; had a terrible headache that was worse than before with Pfizer). Past adverse reactions to the above products included Headache with Pfizer vaccine. Concurrent medical conditions included Immunocompromised.    On 05-Mar-2022, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 05-Mar-2022, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). In March 2022, the patient experienced ILLNESS (severely ill after booster) (seriousness criterion medically significant), HEADACHE (terrible headache that was worse than before with Pfizer) (seriousness criterion medically significant) and HYPOAESTHESIA (her face was numb/left hand on left hand side was numb) (seriousness criterion medically significant). At the time of the report, ILLNESS (severely ill after booster), HEADACHE (terrible headache that was worse than before with Pfizer), HYPOAESTHESIA (her face was numb/left hand on left hand side was numb) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown.            No treatment medications were reported.  Patient was immunocompromised for which she was taking steroids.  Patient had to go by ambulance. Worried about the cost for the ambulance. Patient declined to provide the additional details since the patient had started the work. In the follow-up call it was mentioned that patient would call back anything else needed.  Company Comment: This is a spontaneous case concerning a female patient of an unknown age who was Immunocompromised and had a past COVID-19 Vaccination (3 doses) history with Pfizer Vaccine, who experienced the unexpected serious events of Illness, Hypoesthesia, and Headache. The events were medically significant and occurred on an unknown date (approximately the same month of the vaccination) after receiving a dose (4th dose/Booster dose of the COVID-19 Vaccination Schedule) of mRNA-1273 Vaccine. No clinical or treatment details were given. It was reported that the outcome of the event was unknown. The patient's immunocompromised condition of remains a confounder. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.; Sender's Comments: This is a spontaneous case concerning a female patient of an unknown age who was Immunocompromised and had a past COVID-19 Vaccination (3 doses) history with Pfizer Vaccine, who experienced the unexpected serious events of Illness, Hypoesthesia, and Headache. The events were medically significant and occurred on an unknown date (approximately the same month of the vaccination) after receiving a dose (4th dose/Booster dose of the COVID-19 Vaccination Schedule) of mRNA-1273 Vaccine. No clinical or treatment details were given. It was reported that the outcome of the event was unknown. The patient's immunocompromised condition of remains a confounder. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.