is having pet cat in the house will harm my baby?  

i know many, many people who were raised with cats and dogs, and some young children who are being raied with pets now. no harm has come to anyone i know that was raised with pets.

my advice is keep your cats and love them, just make sure to watch your son around them. babies do not understand that animals can be hurt and can play to roughly with a pet, and then the pet scratches or bites to try to get away from the baby.

as your son gets older, the companionship of animals will greatly increase his compassion for others and his understanding of love on many levels.

i think it is good to raise kids with pets.

My daughter has been around my cats since she was born and she is now four years old. I don't see any problem in having your cats and your baby son. I have never had any problems with my daughter developing anything from being around them. I think its best to socialize kids early with pets :]

Your child will only develope an allergic reaction if this is allready in his system. No allergies come from keeping a cat or dog around, if for all things something would happen it's getting a better immune system. The reason why children nowadays get all kinds of allergic reactions and stuff is because we keep their invironment TOO clean. Scientific research has proven so. Now there is nothing wrong with good hygene, but getting everything and anything out of the way is not a solution to keep your child healthy.

Do mind that cats love to snuggle up to babies and love the warm breath the baby breaths. They can lie down on top of the baby's face because of this and therefor choke the baby. They absolutely have no intention of doing this, but it can happen! Be carefull and allways stay around if your cats go near a baby that can't turn away or get the cat of theirselves.

I don't see how it could effect health or immunity if the animals are kept clean and trained to do their business either outside or in a catbox that gets dumped & cleaned regularly. All my boys grew up around either cats or dogs and all four of them are healthy and strong...then again, I'm not an expert or anything.
However, my old roommate from back in the day made me get rid of my kitten after her baby was born because she was afraid the kitten would smell the formula on the baby and "take her breath" trying to drink the "milk" from her mouth. It seems feasible, but I don't know anyone it has happened to.
Good luck & i hope you find the info you need.