Exodus 11:4

So Moses said, “This is what the Lord says: ‘About midnight I will go throughout Egypt. 5 Every firstborn son in Egypt will die, from the firstborn son of Pharaoh, who sits on the throne, to the firstborn son of the female slave, who is at her hand mill, and all the firstborn of the cattle as well.6 There will be loud wailing throughout Egypt—worse than there has ever been or ever will be again.

Biological disease that targets first borns? Because rhesus negative women miscarry after giving birth to a rhesus positive child? Because rhesus positive means hybrid human which is why the plague also killed the firstborn of cattle?