What Will it Take to End the COVID-19 Pandemic?
It is hard to believe how much life has changed in just a few weeks. With unprecedented economic collateral damage as states issue stay-at-home orders, we all recognize that the end to this global nightmare cannot come soon enough. The trillion-dollar question is how and how quickly — what will it take to stop COVID-19?
In my analysis, there are 4 possible ways to stop COVID-19:
1. A treatment.
2. A vaccine.
3. Herd immunity.
4. Breaking the chain of transmission.
First, a word on the fundamental epidemiology of a viral epidemic. The basic reproduction number of a virus, R0 (R-naught), is the average number of people each infected person infects. It is a measure of transmissibility — how easy it is to catch the virus from an infected person. Characteristics that increase R0 include a longer (potentially contagious) latent period and the ability to survive on surfaces outside of the body — both present in COVID-19. When R0 is greater than 1, a virus ultimately spreads; when R0 is less than 1, a virus eventually disappears. The R0 of COVID-19 has been estimated to be between 2–2.5 based on WHO observation in China. By comparison, the R0 of seasonal flu generally hovers around 1.3.
