Public health experts, including the Centers for Disease Control and Prevention (CDC), confirm that the flu shot is safe while breastfeeding. Major medical organizations strongly recommend the influenza vaccine for nursing mothers. This guidance is based on extensive safety data supporting vaccination for the mother’s protection and for the immunological benefits passed to the infant. The overwhelming scientific consensus confirms the practice is safe and beneficial for both mother and child.
Safety of Flu Vaccines While Breastfeeding
The safety of the influenza vaccine is related to the type administered. The standard injectable flu shot is an inactivated vaccine, containing only non-living, fragmented viral material. Because it contains no live virus, it is impossible for the mother to contract influenza from the shot or transmit a live virus to her baby through breast milk. The non-live components are quickly processed by the mother’s immune system, generating a protective antibody response, and studies confirm the vaccine ingredients are not found in breast milk.
The nasal spray vaccine is a live attenuated influenza vaccine (LAIV), which uses a weakened form of the live virus. While the LAIV is licensed for use in breastfeeding women, the injectable inactivated vaccine is generally preferred. The injectable vaccine is the preferred option because it entirely removes the theoretical risk of viral transmission while also providing a superior antibody response.
Protecting the Infant Through Breast Milk
Getting the influenza vaccine while breastfeeding provides a layer of defense for the nursing infant through passive immunity. After the mother receives the shot, her body rapidly begins to produce targeted antibodies against the specific influenza strains. These protective antibodies are then transferred to the baby via the breast milk.
The transferred antibodies primarily include Immunoglobulin A (IgA) and Immunoglobulin G (IgG). Secretory IgA (sIgA) provides mucosal immunity, coating the baby’s respiratory and gastrointestinal tracts to neutralize pathogens. This protection is especially valuable for infants younger than six months, as they are too young to receive the vaccine themselves. Maternal vaccination combined with continued breastfeeding reduces the incidence of influenza in infants until they can be vaccinated directly at six months of age.
Practical Side Effects and Common Misconceptions
Following the flu shot, a breastfeeding mother may experience typical, temporary side effects that do not interfere with nursing. These common reactions include soreness, redness, or swelling at the injection site, and sometimes a low-grade fever, headache, or mild fatigue. These are signs that the immune system is actively creating protective antibodies, not that the mother has contracted the flu.
A common misconception is that these mild, temporary symptoms necessitate a disruption in breastfeeding, such as “pumping and dumping.” This is entirely unnecessary; neither the vaccine nor the mother’s temporary side effects pose any harm to the infant. Continuing to nurse is encouraged, as the mother’s body is already producing the beneficial antibodies that will be passed through the milk.
Another concern is that the vaccine could cause the baby to get the flu, but this is impossible with the inactivated shot. The vaccine contains no live virus to transmit, and the flu virus itself is not passed through breast milk. The most effective action a mother can take is to receive the vaccine and continue breastfeeding to provide her baby with constant immunological support.