On Sept 13, 2024, WHO announced the prequalification of the first mpox vaccine, MVA-BN.1 WHO's Strategic Advisory Group of Experts (SAGE) on Immunization recommended this vaccine for people at high risk of mpox exposure in the current outbreak, stating that “this vaccine may be used ‘off-label’ in infants, children and adolescents, and in pregnant and immunocompromised people”. 1 Missing from these recommendations are breastfeeding mothers. In 2022, WHO had stated that the MVA-BN vaccine could be used in breastfeeding women.2 However, WHO's new 2024 guidance, which replaced the 2022 recommendations, simply states, “MVA-BN safety and efficacy has not been evaluated in breastfeeding women. Data are not available to assess…the safety of MVA-BN in breastfed infants.”3
MVA-BN contains a weakened, non-replicating virus that cannot cause mpox. Currently, some countries recommend its use in people who are breastfeeding,4 whereas others prefer not to make this recommendation.5 This contradiction has, understandably, led to confusion among health-care workers.