There is no evidence that breastfeeding babies are having side effects, and certainly not severe side effects, after their mothers have been vaccinated against COVID-19.
COVID-19 vaccine deaths
Since the pediatric COVID-19 vaccine trials had not yet started when these children supposedly died, these reports of vaccine deaths in VAERS are almost certainly mistakes.
After sparking much of the vaccine talk, Thomas Hearns announced that it was outrageous to be turning the death of Marvin Hagler into an anti vaccine campaign.
There is no evidence to associate the death of DMX with a COVID-19 vaccine.