All the characteristics of an ultimately deadly infection already exist in the wild: anything that combined the deadliness and incubation period of AIDS with the transmissibility of the common cold.
Correct me if I'm wrong, but aren't there very good reasons why those qualities don't overlap? Analogously it would be literally true to say that we'd be at great risk if threaten by an animal with the killing abilities of a tiger and the reproduction speed and numbers of ants, but such a thing isn't biologically possible.
The theory goes : plagues that are especially deadly must spread through the body extremely quickly. Otherwise, they give the immune system time for the B cells to formulate an antibody. Yet, if the plague spreads quickly, it has a short incubation period, and it means that hosts will die before spreading it. Ebola is thought to fit in this part of the ecology, and this is one reason why the virus is rare.
A virus that spread itself like the flu but also killed like ebola would be pushed by evolution away from these properties because it would kill off i...
The FHI's mini advent calendar: counting down through the big five existential risks. The fourth one is an ancient risk, still with us today: pandemics and plagues.
Pandemics
Current understanding: high
Most worrying aspect: the past evidence points to a risky future
The deathrates from infectious diseases follow a power law with a very low exponent. In layman’s terms: there is a reasonable possibility for a plague with an absolutely huge casualty rate. We’ve had close calls in the past: the black death killed around half the population of Europe, while Spanish Influenza infected 27% of all humans and killed one in ten of those, mostly healthy young adults. All the characteristics of an ultimately deadly infection already exist in the wild: anything that combined the deadliness and incubation period of AIDS with the transmissibility of the common cold.
Moreover, we know that we are going to be seeing new diseases and new infections in the future: the only question is how deadly they will be. With modern global travel and transport, these diseases will spread far and wide. Against this, we have better communication and better trans-national institutions and cooperation – but these institutions could easily be overwhelmed, and countries aren’t nearly as well prepared as they need to be.