Viruses: What They are, How They Spread, and How We Fight Them

Some of the most deadly diseases of the modern era come from viruses — and they’re not even alive.

Viruses are not alive, at least in the classical sense. While they’re made of proteins and genes like living things, they need to interact with living host cells to reproduce. These agents of cellular mayhem have been the cause of history-altering outbreaks and pandemics, from smallpox and polio to HIV and Ebola, but were only discovered at the turn of the 20th century. Since then, we’ve found them in nearly every ecosystem worldwide. Viruses are, and always will be, the world’s experts at going viral.


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