severe back pain (middle to upper); This spontaneous case was reported by a patient family member or friend and describes the occurrence of BACK PAIN (severe back pain (middle to upper)) in a 90-year-old female patient who received mRNA-1273.712 (SPIKEVAX 2024-2025 PFS) for COVID-19 prophylaxis. No Medical History information was reported. In January 2025, the patient received dose of mRNA-1273.712 (SPIKEVAX 2024-2025 PFS) (unknown route) 1 dosage form. In January 2025, the patient experienced BACK PAIN (severe back pain (middle to upper)). The patient was treated with Diclofenac sodium (Voltaren) at an unspecified dose and frequency. At the time of the report, BACK PAIN (severe back pain (middle to upper)) had not resolved. The action taken with mRNA-1273.712 (SPIKEVAX 2024-2025 PFS) (Unknown) was unknown. Patient did not receive vaccines within the past 4 weeks. No concomitant medication was reported. The patient did not experience any additional symptoms or events. This case was linked to US-MODERNATX, INC.-MOD-2025-781607 (E2B Linked Report).; Sender’s Comments: US-MODERNATX, INC.-MOD-2025-781607:Invalid case