First, choose a daycare center that's licensed, which means it's legally bound to follow basic steps (like daily cleaning and diaper changing protocols) to reduce the spread of common daycare infections. Plan ahead so that your child's vaccinations, including flu, are up to date, and make sure they get enough nutritious food and sleep to keep their immune system strong. If you can, discourage thumb sucking and pacifier use, which can carry bacteria and are linked to certain infections.