Vaccinations are important to both maternal and child health. The Advisory Committee on Immunization Practices (ACIP) develops recommendations on how to use vaccines to control disease in the United States. ACIP Vaccine Recommendations and Guidelines include the age(s) when the vaccines should be given, the number of doses needed, the amount of time between doses, and precautions and contraindications.
According to the ACIP’s General Best Practice Guidelines for Immunization in Special Situations, except for smallpox and yellow fever vaccines, neither inactivated nor live-virus vaccines administered to a lactating woman affect the safety of breastfeeding for women or their infants. Although live viruses in vaccines can replicate in the mother, the majority of live viruses in vaccines have been demonstrated not to be excreted in human milk. Inactivated, recombinant, subunit, polysaccharide, and conjugate vaccines, as well as toxoids, pose no risk for mothers who are breastfeeding or for their infants.
Breastfeeding is a contraindication for smallpox vaccination of the mother because of the theoretical risk for contact transmission from mother to infant. Two serious adverse events have been reported in exclusively breastfed infants whose mothers were vaccinated with Yellow Fever vaccine. Until more information is available, Yellow Fever vaccine should be avoided in breastfeeding women. However, when travel of nursing mothers to a Yellow Fever endemic area cannot be avoided or postponed, these women should be vaccinated.
Source: CDC
Link: https://www.cdc.gov/breastfeeding/breastfeeding-special-circumstances/vaccinations-medications-drugs/vaccinations.html