Patient also had some muscle soreness at the vaccination spot; Revaccination with different COVID-19 vaccine; Interchange of vaccine products; drug exposure during pregnancy; This spontaneous prospective pregnancy case was reported by a consumer and describes the occurrence of VACCINATION SITE PAIN (Patient also had some muscle soreness at the vaccination spot), MATERNAL EXPOSURE DURING PREGNANCY (drug exposure during pregnancy), COVID-19 IMMUNISATION (Revaccination with different COVID-19 vaccine) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) in a 34-year-old female patient who received mRNA-1273.815 (SPIKEVAX 2023-2024) (batch no. ASKU) for COVID-19 prophylaxis.     Previously administered products included for COVID-19 prophylaxis: Moderna covid-19 vaccine (prior dose of the Moderna COVID-19 vaccine); for Drug use for unknown indication: Johnson and Johnson COVID-19 vaccine (Patient had previously received a dose of the Johnson and Johnson COVID-19 vaccine) and Influenza vaccine. Past adverse reactions to the above products included No adverse event with Moderna covid-19 vaccine; and No adverse reaction with Influenza vaccine and Johnson and Johnson COVID-19 vaccine.    On 09-Oct-2023, the patient received third dose of mRNA-1273.815 (SPIKEVAX 2023-2024) (unknown route) 1 dosage form. Last menstrual period and estimated date of delivery were not provided. On 09-Oct-2023,  after starting mRNA-1273.815 (SPIKEVAX 2023-2024), the patient experienced MATERNAL EXPOSURE DURING PREGNANCY (drug exposure during pregnancy). On an unknown date, the patient experienced VACCINATION SITE PAIN (Patient also had some muscle soreness at the vaccination spot), COVID-19 IMMUNISATION (Revaccination with different COVID-19 vaccine) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). The patient was treated with PARACETAMOL (TYLENOL) at an unspecified dose and frequency. On 09-Oct-2023, MATERNAL EXPOSURE DURING PREGNANCY (drug exposure during pregnancy) had resolved. At the time of the report, VACCINATION SITE PAIN (Patient also had some muscle soreness at the vaccination spot) had not resolved and COVID-19 IMMUNISATION (Revaccination with different COVID-19 vaccine) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown.        For mRNA-1273.815 (SPIKEVAX 2023-2024) (Unknown), the reporter did not provide any causality assessments.   Concomitant medications were not reported.  Company comment:  This spontaneous case concerns a 34  year  old female patient, with no relevant medical history reported, and maternal exposure during pregnancy who experienced the expected, non - serious event of vaccination site pain after receiving a dose of Spikevax 2023-2024 vaccine (Andusomeran). Latency cannot be properly assessed since exact onset date was not provided. The outcome was reported as not recovered. The patient previously received Janssen COVID-19 vaccine and a dose with Moderna COVID-19 vaccine (interchange of vaccine product and revaccination with different COVID-19 vaccine was considered). No further clinical details were provided for medical reviewing. Gestational period was not disclosed. The benefit-risk relationship of Spikevax 2023-2024 vaccine (Andusomeran) is not affected by this report.