Vaccine goes into the muscles of the upper arm, most usually, and it really just stays there. It was considered very unlikely that any components of the vaccine would manage to survive their journey into the blood and then get into the breast milk. But researchers have not found any components of vaccines in Breast Milk. A case of no vaccine itself in the milk. What about antibodies? Caus they'repretty important. And people who've had covid will generate antibodies also,. These are what provide us with some tection, we hope, going forward.