Mother & MIL mad I dont want them kissing my baby

I made a post on Facebook saying I don't want ANYBODY kissing my baby. It wasnt addressed to anyone but just a message in general that was about RSV. My mom and MIL both got mad that I dont want them kissing the baby when she's born. They think I'm being rude and said they are going to kiss her anyways. My boyfriend is standing up for me because he knows I'm paranoid but they continue to argue with us regardless. I dont want to take any chances just because they want to kiss my baby. I thought my mother would understand but she was being upset about it saying she has to hold her through a glass wall and over exaggerating 🙄 and my MIL is saying its rude and that she is going to kiss the baby anyways after sanitizing her mouth. I dont understand why they all think its such a big deal, they wont die from kissing my baby but my baby may die from them kissing her!