Hi,
Chemo treatments can and usually do affect blood counts, white/red cells as well as platelets. These numbers usually come back up bythem selves, but at times you will need to get help from extra medication.
While undergoing treatments, you will need to be carefull any ways, so the patient should get as much rest as necessary to allow their bodies to rebuild and stay away from public places as much as possible to reduce chances of getting infection, etc.
Don't worry, there are plenty of ways you can get help.
Bests to you and all.