Vetedine

Prior to biopsies, the skin and inguinal area were cleaned with povidone iodate solution (Vetedine^®, Vetoquinol SA, Lure, France). Biopsies of 8 mm in diameter were collected at untreated sites and 24, 48, and 72 h after injection. A total of eight skin biopsies were performed for each animal (Figure S1 in Supplementary Material). These biopsies induced insignificant inflammatory responses in comparison to i.d. injection of MVA (Figure S2 in Supplementary Material). The inguinal LNs were collected 24 h post injection. Blood was collected in K3-EDTA tubes (Greiner Bio-One, Frickenhausen, Germany) for cell blood counting (HmX, Beckman Coulter, Roissy, France), plasma collection, and flow cytometry. Plasma for cytokine analysis was collected after 10 min of centrifugation at 2,000 g. Blood (500 µl) collected in lithium heparin (Vacutainer BD) was mixed with 1 ml tempus RNA (Thermofischer Scientific, Waltham, MA, USA) for transcriptomic analysis. Tissue biopsies for transcriptomic profiling were preserved in 1 ml RNA later solution (Qiagen, Hilden, Germany) at 4°C overnight and then stored at −20°C.

The pregnant Préalpes-du-Sud ewe selected to give birth to two lambs was subjected to classical cesarean surgery. After stimulation of the respiratory function, right after birth, they were positioned in lateral decubitus and received intranasally one to two drops of doxapram (Dopram^®, Vetoquinol, Lure, France) to stimulate the respiratory rate. The umbilical cord was disinfected with Vetedine^® (Vetoquinol, Lure, France) and newborns were then placed together in close contact in the housing box, in a dry and warm environment, under a heating lamp. After 30 min, one of the two lambs was operated.

Prior to biopsies, the site of injection was cleaned with a povidone iodate solution (Vetedine^®, Vetoquinol SA, Lure, France). Skin biopsies were 8 mm in diameter. For the subcutaneous route, 5 x 1.5 cm (ellipse shape) deep skin biopsies were performed with a scalpel. Muscular biopsies were conducted after anaesthesia of the animal with tiletamin/zolazepam (Zolétil^®, 5 mg/kg). Targeted muscles were the triceps, biceps, and quadriceps. Biopsies were surgically removed at 24 or 48 h after injection.