Perspective

Routine maternal vaccination safe for breastfeeding mothers, infants

Photo of Philip Anderson
Philip O. Anderson

A review published in Breastfeeding Medicine reinforces that no routine vaccinations are contraindicated for nursing mothers.

“The most important takeaway message is that breastfeeding is not an impediment to the infant or mother receiving routine vaccinations at the recommended times,” Philip O. Anderson, PharmD, a health sciences clinical professor of pharmacy in the Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California San Diego, told Infectious Diseases in Children.

In his review, Anderson wrote that no evidence exists that inactivated or recombinant vaccines can harm breastfed infants. Although infection may occur with live-attenuated vaccines, most live vaccines are not passed through breastmilk and do not harm infants. Anderson said there are two exceptions — specifically, yellow fever and smallpox vaccines. These should be avoided while breastfeeding, he wrote.

Breastfeeding women can receive either the live-attenuated or inactivated influenza vaccine. In a study of women who were vaccinated during the third trimester and breastfed their infants for an average of 14 weeks, infants had a 36% decrease in respiratory illness with fever and a 63% decrease in laboratory-confirmed influenza during the first 6 months of life compared with controls.

Photo of mother breastfeeding her infant 
Source: Adobe

Anderson noted that pregnant women need a dose Tdap vaccine with every pregnancy. Mothers who are vaccinated after 20 weeks’ gestation have higher levels of anti-pertussis immunoglobulin A in their breast milk compared with unvaccinated mothers. Furthermore, a study of previously vaccinated infants found that at 21 to 40 months of age, breastfed infants had higher immunoglobulin G levels against diphtheria, higher secretory IgA levels in saliva against diphtheria and tetanus, and higher fecal immunoglobulin M against tetanus compared with infants who were fed formula.

According to Anderson, there is “no clear evidence” that the live-attenuated measles or mumps vaccine virus is excreted into breastmilk. Cases of pediatric infections have been reported, he wrote, but these infections are “well-tolerated” because the virus is attenuated.

Furthermore, women with risk factors for hepatitis A and B, meningitis, Haemophilus and Pneumococcus are not contraindicated for vaccination. Women who breastfeed are also not contraindicated for many specialty vaccines, including cholera, anthrax, rabies and typhoid.

“No special precautions need to be taken,” Anderson said. “The only exceptions are some unusual, nonroutine vaccines. Yellow fever vaccine is used only for travel to endemic areas, and the smallpox and adenovirus vaccines are used primarily in military personnel.” – by Katherine Bortz

Disclosure: Anderson reports no relevant financial disclosures.

Photo of Philip Anderson
Philip O. Anderson

A review published in Breastfeeding Medicine reinforces that no routine vaccinations are contraindicated for nursing mothers.

“The most important takeaway message is that breastfeeding is not an impediment to the infant or mother receiving routine vaccinations at the recommended times,” Philip O. Anderson, PharmD, a health sciences clinical professor of pharmacy in the Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California San Diego, told Infectious Diseases in Children.

In his review, Anderson wrote that no evidence exists that inactivated or recombinant vaccines can harm breastfed infants. Although infection may occur with live-attenuated vaccines, most live vaccines are not passed through breastmilk and do not harm infants. Anderson said there are two exceptions — specifically, yellow fever and smallpox vaccines. These should be avoided while breastfeeding, he wrote.

Breastfeeding women can receive either the live-attenuated or inactivated influenza vaccine. In a study of women who were vaccinated during the third trimester and breastfed their infants for an average of 14 weeks, infants had a 36% decrease in respiratory illness with fever and a 63% decrease in laboratory-confirmed influenza during the first 6 months of life compared with controls.

Photo of mother breastfeeding her infant 
Source: Adobe

Anderson noted that pregnant women need a dose Tdap vaccine with every pregnancy. Mothers who are vaccinated after 20 weeks’ gestation have higher levels of anti-pertussis immunoglobulin A in their breast milk compared with unvaccinated mothers. Furthermore, a study of previously vaccinated infants found that at 21 to 40 months of age, breastfed infants had higher immunoglobulin G levels against diphtheria, higher secretory IgA levels in saliva against diphtheria and tetanus, and higher fecal immunoglobulin M against tetanus compared with infants who were fed formula.

According to Anderson, there is “no clear evidence” that the live-attenuated measles or mumps vaccine virus is excreted into breastmilk. Cases of pediatric infections have been reported, he wrote, but these infections are “well-tolerated” because the virus is attenuated.

Furthermore, women with risk factors for hepatitis A and B, meningitis, Haemophilus and Pneumococcus are not contraindicated for vaccination. Women who breastfeed are also not contraindicated for many specialty vaccines, including cholera, anthrax, rabies and typhoid.

“No special precautions need to be taken,” Anderson said. “The only exceptions are some unusual, nonroutine vaccines. Yellow fever vaccine is used only for travel to endemic areas, and the smallpox and adenovirus vaccines are used primarily in military personnel.” – by Katherine Bortz

Disclosure: Anderson reports no relevant financial disclosures.

    Perspective
    Bernhard L. “Bud” Wiederman

    Bernhard L. “Bud” Wiederman

    The article by Anderson nicely summarizes the thinking of the CDC about vaccination issues for breastfeeding mothers. This work is unlikely to change how clinicians now counsel breastfeeding women; however, one caveat and a couple of important exceptions should be underscored.

    The caveat is that rubella virus has been shown to be excreted in human breastmilk from mothers who received postpartum rubella vaccine. This was well-documented in landmark studies by Losonsky and colleagues and subsequently by Hisano and colleagues. Losonsky and colleagues demonstrated seroconversion to rubella in a minority of breastfed infants, but no clinical illness occurred. Even though infants may acquire rubella virus from breastmilk of recently immunized mothers, it does not appear to have harmful effects for these infants.

    Secondly, it is important to highlight two vaccines that breastfeeding mothers should avoid: yellow fever vaccine and smallpox vaccine. Yellow fever vaccine is increasingly required for travel to certain countries, and the virus is transmissible to infants through breastmilk. At least three infants aged younger than 1 month have developed yellow fever vaccine-associated neurologic disease associated with maternal viral shedding in breastmilk. Breastfeeding women are officially cautioned against receiving yellow fever vaccination, although the relative risks and benefits of immunization should be weighed on an individual basis.

    Smallpox vaccine is contraindicated for breastfeeding women, given the ease with which the virus can be spread from the vaccination site to other individuals.

    Finally, practitioners may wish to alert breastfeeding mothers who are planning international travel to the CDC’s Yellow Book section on “Travel & Breastfeeding.”

    Reference:

    Shealy KR. Travel & breastfeeding. In: CDC. Yellowbook 2018: International Travel with Infants & Children. Washington, DC: CDC; 2018. https://wwwnc.cdc.gov/travel/yellowbook/2018/international-travel-with-infants-children/travel-and-breastfeeding. Accessed April 24, 2019.

    • Bernhard L. “Bud” Wiederman, MD, MA
    • Attending in infectious diseases
      Children’s National Health System
      Professor of pediatrics
      The George Washington University School of Medicine & Health Sciences

    Disclosures: Wiederman reports no relevant financial disclosures.