David Shaywitz writes:

Who bears responsibility for the COVID-19 pandemic?

While a detailed forensic accounting will ultimately reveal the contribution of people and institutions to the current crisis, we must take care not to lose sight of the most important culprit: the unique character of the virus itself.

To a first approximation, a virus can be defined by two parameters:

R₀ (“R-naught”) is the basic reproduction number, which measures how transmissible the virus is. Meaning: If you’re a typical patient who has knowingly or unknowingly contracted the virus, how many new people will you infect on average?

The Case Fatality Rate (CFR) measures how lethal the virus is. Meaning: If you are diagnosed with an infection, how likely are you to die?

Viruses that are extremely deadly, such as MERS and ebola, have tended to be relatively self-limiting, in part because they are so lethal. Less deadly viruses, such as the measles, are incredibly contagious—but not especially deadly.

SARS-CoV-2, the virus behind COVID-19, occupies what former FDA Commissioner Scott Gottlieb calls “the middle space.” It is, he explains, “lethal enough to be very virulent, very threatening, but transmissible enough that it could reach around the world.” It is, in a phrase, “the perfect pathogen.”

Beyond it’s descriptive numbers, SARS-CoV-2 harbors additional characteristics which make it especially problematic. [Continue reading…]