Fig 1. The breastfeeding surrogate mother experiment.

Adult female A129 mice were iv. infected with 10⁶ PFU per mouse of DENV1. One week post-infection after virus clearance, the females were mated with naïve adult males. Age-matched naïve females were also mated concurrently. At birth, pups born to either DENV1-immune or naïve mothers were switched and nursed by naïve or dengue-immune mothers respectively. Control groups comprised of mice nursed by birth mothers were also included. DD: Born to and nursed by dengue-immune mother; DN: Born to dengue-immune mother, but nursed by naïve mother; ND: Born to naïve mother, but nursed by dengue-immune mother; NN: Born to and nursed by naïve mother.