According to the United States Centers for Disease Control and Prevention Advisory Committee, “The Influenza vaccine does not affect the safety of the mothers who are breastfeeding or their infants. Breastfeeding does not adversely affect the immune response and is not a contradiction for vaccination.”
You cannot get the flu from the shot as it is a dead virus.
Vaccines can even provide some protection to your baby. Infants cannot have the flu vaccine until they are 6 months old. Studies have shown they pick up some protection if their mothers get annual flu shots, because they’re made to protect against bacterial infections that may pass though the breast milk.
Even if you get the flu, in most cases it is best to continue breastfeeding because your baby will gain protection from antibodies in your breast milk. In fact, with most viral infections, such as colds, sore throats, and stomach viruses, you are infectious but starting to produce antibodies before you have any symptoms. So If you don’t stop the breastfeeding, your baby gets protection both before you knew you were sick and throughout your illness. Don’t worry these common viruses are not passed through the milk to your baby.
If you are pregnant it is very important that you get the flu vaccine. Researchers have calculated that the risk of fetal death was nearly twice as high for women who were not vaccinated as it was in vaccinated women.