Chat about Novel Coronavirus - 2019-nCoV - COVID-19

Zeynep Tufekci on the new variant - written for a US audience but still holds true for here

To understand the difference between exponential and linear risks,
consider an example put forth by Adam Kucharski, a professor at the
London School of Hygiene & Tropical Medicine who focuses on
mathematical analyses of infectious-disease outbreaks. Kucharski
compares a 50 percent increase in virus lethality to a 50 percent
increase in virus transmissibility. Take a virus reproduction rate of
about 1.1 and an infection fatality risk of 0.8 percent and imagine
10,000 active infections—a plausible scenario for many European
cities, as Kucharski notes. As things stand, with those numbers, we’d
expect 129 deaths in a month. If the fatality rate increased by 50
percent, that would lead to 193 deaths. In contrast, a 50 percent
increase in transmissibility would lead to a whopping 978 deaths in
just one month—assuming, in both scenarios, a six-day
infection-generation time.

Transmissibility increases can quickly—very quickly—expand the
baseline: Each new infected person potentially infects many more
people. Severity increases affect only the infected person. That
infection is certainly tragic, and this new variant’s lack of increase
in severity or lethality thankfully means that the variant is not a
bigger threat to the individual who may get infected. It is, however,
a bigger threat to society because it can dramatically change the
number of infected people. To put it another way, a small percentage
of a very big number can easily be much, much bigger than a big
percentage of a small number.