"The black plague" may not, "a black plague" may. In other words, Y. pestis might still be treatable with modern antibiotics and is well controlled with modern

"The black plague" may not, "a black plague" may. In other words, Y. pestis might still be treatable with modern antibiotics and is well controlled with modern sanitization. But if MERS-CoV and influenza got together, or NDM-1 genes horizontally transferred to group A strep, you could end up with a highly contagious and highly fulminant threat.