Breast Cancer; This report was received from business partner, with assigned Manufacturer Control Number of 2205USA004695.  Information has been received from the investigator regarding a 73-year-old female subject enrolled in a study.  The subject's concurrent conditions included myopia, seasonal allergy, depression, hypertension, hypercholesterolaemia, essential tremor, type 2 diabetes mellitus, and breast cyst. She was post menopausal. The subject's medical history was not reported. Concomitant therapies included ascorbic acid (+) betacarotene (+) copper (+) nicotinamide (+) selenium (+) tocopherol (+) xantofyl (+) zinc (LUTEIN +), calcium citrate, vitamins no otherwise specified (NOS) (MULTIVITAMINUM), colecalciferol (Vitamin D3), atorvastatin, acetylsalicylic acid (ASPIRIN), carvedilol, venlafaxine, losartan and glimepiride.  On 11-MAY-2022, the subject underwent a right breast biopsy (results not reported). On 12-MAY-2022, the subject was randomized into the study protocol, and on that same date, at 16:52, she was vaccinated with the first dose of pneumococcal vaccine, polyvalent (23-VALENT) (V110), or pneumococcal 15v conj vaccine (CRM197) (V114) or matching placebo intramuscularly (IM) on her left arm; and at 16:53, she was also vaccinated with single SARS-COV-2 vaccine (mRNA-1273) at a dose of 50 microgram IM, on her right arm. Both vaccines were administered as prophylaxis for pneumococcal infection. Those were the only reported doses administered to the subject; also were the last doses prior to the event.  The subject called to the site and reported that she was diagnosed with stage 1 breast cancer (Grade 2) by the Oncologist on 16-MAY-2022 at 16:35. The subject denied any signs and symptoms. The subject was waiting to have surgery and on 31-MAY-2022; procedures of lumpectomy were performed which result was normal. Medical records were pending. The subject had no history or risk factors. The site continued to wait on pending records. There was no information reported regarding the follow-up clinical course. At the reporting time, the subject had not recovered from breast cancer (Grade 2).  The action taken with both study vaccines regarding the event was reported as not applicable.  The investigator considered breast cancer (Grade 2) to be not related to the study vaccines nor to the study procedure. The investigator considered breast cancer (Grade 2) to be a medically significant event.  Updated information has been received on 22-JUN-2022 from the investigator. Details of the concomitant therapies were updated.  Company Causality Assessment: Based on the clinically relevant information currently available for this individual case, the reported event of breast cancer is considered unlikely related to investigational vaccines. The evidence is not sufficient to suggest a relationship between the investigational vaccines and the reported serious adverse event. The causality assessment is impacted by the confounding factor of the implausible temporal relationship as the event was diagnosed four days after last dose of study vaccine and by breast cancer being the most common malignancy diagnosed in women worldwide, with the risk increasing in older age. However additional clinical details and medical history was not yet provided.  Company Comment- No changes to investigational vaccines are warranted at this time. Business partner continues to monitor the safety profile of 23-valent pneumococcal polysaccharide vaccine (V110) or 15-valent pneumococcal conjugate vaccine. Moderna continues to monitor the safety profile of SARS-CoV-2 mRNA (mRNA  1273) Vaccine.  Company Comment: This case concerns a 73-year-old White female subject with medical history of myopia, seasonal allergy, depression, hypertension, hypercholesterolaemia, essential tremor, type 2 diabetes mellitus, breast cyst and post-menopausal, who experienced the unexpected adverse event breast cancer.  The event occurred 5 days after the first dose of blinded V110 and mRNA-1273 vs Placebo.  The event was reported as not resolved and was assessed as not related with study drug in accordance with the investigator´s assessment due to lack of biological plausibility and short temporal association. Subject´s age and PMH of breast cyst could be a contributory risk factor for the event.; Reporter's Comments: Company Comment: This case concerns a 73-year-old White female subject with medical history of myopia, seasonal allergy, depression, hypertension, hypercholesterolaemia, essential tremor, type 2 diabetes mellitus, breast cyst and post-menopausal, who experienced the unexpected adverse event breast cancer.  The event occurred 5 days after the first dose of blinded V110 and mRNA-1273 vs Placebo.  The event was reported as not resolved and was assessed as not related with study drug in accordance with the investigator´s assessment due to lack of biological plausibility and short temporal association. Subject´s age and PMH of breast cyst could be a contributory risk factor for the event.