Yes I’m sure Africans are at a disadvantage with all diseases. Malnourished in many, if not most, cases. But of course there are vulnerable people everywhere, children, old people, people who are already sick in some way. Not every single person died of smallpox or plague either, but an awful lot did.
Thankfully, your ancestors and mine survived the plague and smallpox and various other scourges of humanity. Amazing, huh?