Factors promoting or inhibiting transmission of virus by breast feeding
| Promoting | Inhibitory | |
| Milk viral load/infected milk cell count | Antiviral antibody32 | |
| Clinical mastitis, abscess20 27 | TGF-β33 | |
| Subclinical mastitis38 | High carotenoid levels34 | |
| Multiple maternal viral infections | Lactoferrin35 | |
| Mixed feeding11 | Protease inhibitor SLP136 | |
| Prematurity, mouth ulcers in infant | Lipid molecules37 | |
| RANTES, GM-CSF28 29 | Specific T lymphocyte killing | |
| Lysozyme, mucins | ||
| Antiviral drugs | ||
| Unclear: Maternal nutrition (e.g. antioxidants, lipids, trace elements, vitamins), period of lactation, lactation history | ||