The Herpes Zoster Virus (also known as the Varicella Zoster Virus) causes chickenpox and shingles.

Chickenpox is the primary infection that often starts with mild cold symptoms. The lesions spread throughout the body and are infectious, often for a few weeks.

After having chickenpox illness, the virus lives in the body, and settles somewhere in the brain or spinal system. Shingles is the reactivation of this latent virus and can cause lesions along a single dermatome. People with shingles develop localized lesions that stay on one side of the body, meaning that they do not cross the midline.

For more information on chickenpox and shingles, please visit the CDC Pink Book.

Newborns have a higher risk of death from chickenpox when the birthing parent develops the illness between 5 days before delivery and 2 days after delivery because the newborn has not received parental antibodies via transplacental transfer. In this situation, the newborn should be separated from their birthing/lactating parent until that parent has no new lesions and is no longer infectious.¹

The chickenpox virus, either wild type or the vaccine strain, has NOT been shown to be transmitted by human milk. Therefore, a lactating person who has chickenpox can provide freshy expressed breastmilk to their infant as long as there are no open lesions that come in contact with the pump or on the nipple-areolar complex.^1,2 Parents should be counseled on strict contact precautions and lesions should be kept covered to avoid infant exposure. If lesions are present on the nipple-areolar complex, then milk should be expressed regularly to maintain milk production and discarded.

Lactating parents who develop a localized herpes zoster outbreak (also known as shingles) should practice contact precautions, by keeping the lesions covered so that the infant is not exposed to the lesions. Breastfeeding is safe if the infant is not exposed to the herpes zoster lesions while breastfeeding. If lesions are present on the nipple-areolar complex, then milk should be expressed regularly to maintain milk production and discarded.¹