Originally Posted by
oriental flyer
According to a top HK medical official , corona virus is expected to infect 60% of the worlds population unless containment measures are successful
I saw this figure a couple of days ago, based on the infection rate of 2.5 new cases per case, and wondered how they got this figure.
Of course the answer is that if (almost) everyone around you is susceptible to the virus, then on average you infect 2.5 of them, but if 60% of the people around you are immune due to prior infection, then you'll infect only one new case, and of course as soon as R drops below 1, the pandemic fizzles.