Daycare sent a hand foot and mouth notice. What do I do with the newborn at home?

Aarav's playschool sent a message that two kids in his group have HFMD. He seems fine right now, no fever, no spots, but I know it takes a few days to show. My worry is the baby. She is 4 months old and I'm not sure how serious HFMD is for infants. Do I keep Aarav home for the week even though he's not sick? Do I separate them at home? He literally cannot stay away from her for 10 minutes. Pune mums, has anyone dealt with this with a newborn in the house? What did your paediatrician say?