Can Breastfeeding Transmit Yellow Fever After Maternal Vaccination?

A five-week old infant almost certainly contracted a vaccine strain of yellow fever virus through breastfeeding. The yellow fever vaccine is a live-virus vaccine; it has been in use since the 1940s.

When the infant was 10 days old, the mother received travel vaccinations including one for yellow fever. Breastfeeding continued after the vaccinations.

According to Science Daily:

"The baby showed no sign of insect bites, had not been in contact with sick people, was not exposed to animals in Canada or elsewhere, had no history of herpes infections in family members and had not had any vaccinations prior to his symptoms."

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