I found the VAERS report of breastfed infant death after mother received 2nd Pfizer vaccine on 3/17/20. The 3/17/20 date appears to be in error because it lists "DateDied" 03/20/2021. Date reported 4/4/21.
"Patient received second dose of Pfizer vaccine on March 17, 2020 while at work. March 18, 2020 her 5 month old breastfed infant developed a rash and within 24 hours was inconsolable, refusing to eat, and developed a fever. Patient brought baby to local ER where assessments were performed, blood analysis revealed elevated liver enzymes. Infant was hospitalized but continued to decline and passed away. Diagnosis of TTP. No known allergies. No new exposures aside from the mother's vaccination the previous day."
You can find this by going to https://vaers.hhs.gov/data.html
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Search Data for "Breastfed"
Data was at row 71,030 of my download.