Monkeypox Vaccine use while Breastfeeding

Summary of Use during Lactation

The Centers for Disease Control and Prevention and several health professional organizations state that vaccines given to a nursing mother do not affect the safety of breastfeeding for mothers or infants and that breastfeeding is not a contraindication to monkeypox vaccine.[1-3] Mpox vaccine does not replicate and behaves like a non-live vaccine and non-live vaccines are generally considered to be acceptable during breastfeeding.[4] The US Centers of Disease Control and Prevention states that if mpox vaccine is required by the mother, it is not a reason to discontinue breastfeeding. Vaccination can be offered to pregnant or breastfeeding women who are otherwise eligible. The risks and benefits of the vaccine should be discussed with the patient using shared decision-making.[5,6] Individuals with Mpox should feed their infants with pasteurized donor milk or infant formula until all of their lesions are healed. Numerous other safety precautions are advised for mothers with Mpox.

Drug Levels

Maternal Levels. Milk samples were collected from a nursing mother the day before and at 2, 6, 20, 36, and 72 hours and 7 and 14 days and 10 weeks after receiving the first dose of intradermal smallpox and monkeypox vaccine, live, nonreplicating (Jynneos, Bavarian Nordic). A second dose was given at 12 weeks and milk samples were taken at 3 hours, 3 days, and 2 and 12 weeks after the dose. Milk IgA against 3 vaccine antigens increased 0.9- to 2.2-fold 2 weeks after dose 2, reaching a peak titer increase of 1.1- to 2.7-fold at 12 weeks after dose 2. Secretory Ab levels increased to 1.1- to 2-fold at 2 weeks after dose 2 and reached a peak of 2- to 3.2-fold increase at the 12-week time point. IgA and sAb responses in milk exhibited correlation, suggesting most milk IgA was sIgA. No vaccine protein or DNA components were detected in the milk samples.[7]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

References

1.

Kroger A, Bahta L, Long S, et al. CDC. General Best Practices for Immunization. 2024. https://www​.cdc.gov/vaccines​/hcp/acip-recs​/general-recs/index.html

2.

Kimberlin DW, Brady MT, Jackson MA, et al. Red Book: 2018 Report of the Committee on Infectious Diseases. 31st ed. Elk Grove Village, IL: American Academy of Pediatrics. 2018.

3.

Gruslin A, Steben M, Halperin S, et al. Immunization in pregnancy: No. 220, December 2008. Int J Gynaecol Obstet 2009;105:187-91. [PubMed: 19367691]

4.

Anderson PO. Maternal vaccination and breastfeeding. Breastfeed Med 2019;14:215-7. [PubMed: 30888205]

5.

Centers for Disease Control and Prevention. Smallpox/Monkeypox VIS. June 1, 2022. https://www​.cdc.gov/vaccines​/hcp/vis/vis-statements​/smallpox-monkeypox.html

6.

Centers for Disease Control and Prevention. Mpox clinical care and treatment during pregnancy. January 30, 2025. https://www​.cdc.gov/mpox​/hcp/clinical-care/pregnancy.html

7.

Yang X, Fox A, DeCarlo C, et al. Unique kinetics of the human milk antibody response to JYNNEOS vaccine for prevention of monkey pox: A case study. Breastfeed Med 2024;19:974-9. [PMC free article: PMC11655390] [PubMed: 39360771]

Substance Name

Monkeypox Vaccine

Drug Class

Breast Feeding

Lactation

Milk, Human

Vaccines