Newborn with toddler at home

Hi mummies, I have a 1 month old and a 19 month old. This has been our second hospitalisation with my 1 month old, both times due to fever. Though we sleep in separate rooms and my 19 month don’t really interact with the younger sibling, younger sibling still falls sick. Are there any tips on how to manage this? Btw 19 month old is in preschool and hence he falls sick pretty often too :(