I was incontinent on Friday. I couldn't even get up to go to the bathroom; I felt Week when I had left, and I came right home.; This spontaneous case was reported by a patient and describes the occurrence of ASTHENIA (I felt Week when I had left, and I came right home.) in an 81-year-old male patient who received mRNA-1273.815 (SPIKEVAX 2023-2024) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product TAMSULOSIN for an unknown indication.    Previously administered products included for Product used for unknown indication: PFIZER BIONTECH COVID-19 VACCINE (over a year ago), PFIZER BIONTECH COVID-19 VACCINE (over a year ago) and PFIZER BIONTECH COVID-19 VACCINE (over a year ago). Past adverse reactions to the above products included No adverse event with PFIZER BIONTECH COVID-19 VACCINE, PFIZER BIONTECH COVID-19 VACCINE and PFIZER BIONTECH COVID-19 VACCINE.   On 02-Nov-2023 at 3:00 PM, the patient received fourth dose of mRNA-1273.815 (SPIKEVAX 2023-2024) (unknown route) 1 dosage form. On an unknown date, the patient started TAMSULOSIN (unknown route) at an unspecified dose. On 02-Nov-2023, the patient experienced ASTHENIA (I felt Week when I had left, and I came right home.) (seriousness criterion medically significant). On 03-Nov-2023,  after starting mRNA-1273.815 (SPIKEVAX 2023-2024), the patient experienced INCONTINENCE (I was incontinent on Friday. I couldn't even get up to go to the bathroom). At the time of the report, ASTHENIA (I felt Week when I had left, and I came right home.) had not resolved and INCONTINENCE (I was incontinent on Friday. I couldn't even get up to go to the bathroom) outcome was unknown.            Concomitant medication not reported.   The patient had vaccine on 2 Nov 2023 and had very serious reactions from that vaccination. She was still down in that 4 days later. After vaccination she felt weak when she had left, and she case home. She did not eat any supper or anything and went to bed. On 3 Nov 2023 she was not able to get out of bed at all. She was incontinent on that day. She was not able to get up to go to the bathroom. She took Tamsulosin as a treatment and that kept her from getting up four times a night to go to the bathroom. 6 hours later that she got her shot.  The patient had taken vitamins.  Company Comment: This is a spontaneous case concerning an 81-year-old, male patient with no reported medical history, who experienced the serious (due to medically significant), unexpected event of Asthenia, and a non-serious unexpected event of Incontinence. The event Asthenia occurred on the same day after the first dose of mRNA-1273.815 (SPIKEVAX 2023-2024) administered as fourth dose of COVID-19 vaccination schedule, and the event Incontinence occurred the following day after vaccination. The patient had received 3 doses of Comirnaty vaccines over a year ago. As per the report, the patient felt weak after vaccination, had not eaten any supper or anything, and went to bed. The following day he could not get out of bed at all, and he was incontinent; as reported, "he couldn't even get up to go to the bathroom". The patient was under treatment with Tamsulosin "that kept the patient from getting up four times a night to go to the bathroom." The outcome of the events was not recovered. The event Incontinence was considered not related to the vaccine based on lack of biological plausibility. Tamsulosin and Age are suggestive of underlying micturition disorder. The benefit-risk relationship of mRNA-1273.815 (SPIKEVAX 2023-2024) is not affected by this report.