Hi! You can fly with your baby if he is not suffering from any congenital heart or lung problems, means if he is absolutely normal. In view of the current scenario you have to be very careful regarding standerd precautions like social distancing from other travellers and using sanitizers frequently. Due to variation in the air pressure during take off and landing, there can be ear pain,  breast feeding the baby or using pacifier at this time can prevent this Take the baby over lap.Usually the flight attendants allow you to do that, and it's safe.

Under normal circumstances you can take your child on flight.  Only precaution is , feed your baby while takeoff and landing. Sucking releases pressure buildup in ear. But now during Corona crisis,  you have to take precautions for prevention of Corona infection too