Received Jul 3, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| COVID19 | COVID19 (COVID19 (MODERNA)) | MODERNA | UNK | — | IM |
Breast cancer that progressed pretty bad a few years ago/ended up with breast cancer right after she took the vaccine; This spontaneous case was reported by a consumer and describes the occurrence of BREAST CANCER (Breast cancer that progressed pretty bad a few years ago/ended up with breast cancer right after she took the vaccine) in a female patient of an unknown age who received SPIKEVAX NOS (SPIKEVAX NOS) for COVID-19 prophylaxis. No Medical History information was reported. On an unknown date, the patient received dose of SPIKEVAX NOS (SPIKEVAX NOS) (Intramuscular use) 1 dosage form. On an unknown date, the patient experienced BREAST CANCER (Breast cancer that progressed pretty bad a few years ago/ended up with breast cancer right after she took the vaccine) (seriousness criterion medically significant). At the time of the report, BREAST CANCER (Breast cancer that progressed pretty bad a few years ago/ended up with breast cancer right after she took the vaccine) outcome was unknown. The action taken with SPIKEVAX NOS (SPIKEVAX NOS) (Intramuscular use) was unknown. Concomitant medications were not reported. It was reported that patient was perfectly healthy. Reporter stated that, patient got breast cancer right after she took the vaccine and that progressed pretty bad a few years ago. When agent asked reporter if the patient had received the covid vaccine of the 2025-2026 season, reporter declined and stated that "it was the one before that". Reporter did not know if the patient got cancer from the vaccine. Reporter wanted to know if cancer was one of the side effects of Moderna covid vaccine. Treatment information was not reported. Initial and live follow-up received on 24-Jun-2026 has been processed together in the same case cycle. This case was linked to US-MODERNATX, INC.-MOD-2026-798164 (E2B Linked Report). Most recent FOLLOW-UP information incorporated above includes: On 24-Jun-2026: Live follow-up received contains non-significant information. Reporter's email and reference number were added, event verbatim and narrative were updated.; Reporter's Comments: The company assessed the event of BREAST CANCER as not related to suspected vaccine due to lack of biological plausibility and very short onset latency. Missing information regarding type of cancer, age of patient and medical history precludes proper medical assessment. The benefit-risk relationship of the product is not affected by this report.; Sender's Comments: US-MODERNATX, INC.-MOD-2026-798164:Invalid case for multiple people