in an otherwise fully susceptible, well-mixed population

[GoodTaste]

Does "otherwise" here mean "in another way"? If so, "in (this way)" would be not "fully susceptible". It puzzles me.

=====================
Epidemiologists can estimate the proportion of a population that needs to be immune before herd immunity kicks in. This threshold depends on the basic reproduction number, R0 — the number of cases, on average, spawned by one infected individual in an otherwise fully susceptible, well-mixed population, says Kin On Kwok, an infectious-disease epidemiologist and mathematical modeller at the Chinese University of Hong Kong. The formula for calculating the herd-immunity threshold is 1–1/R0 — meaning that the more people who become infected by each individual who has the virus, the higher the proportion of the population that needs to be immune to reach herd immunity.

Source: Nature
https://www.nature.com/articles/d41586-020-02948-4

 

[SoothingDave]

"Otherwise" doesn't belong there.

 

[GoodTaste]

"Otherwise" doesn't belong there.

Do you mean that it should be removed?

 

[SoothingDave]

Yes. It doesn't fit. I would expect something like "one infection in an otherwise immune population." "Otherwise" tells you one thing is contrary to the other.

 

[GoesStation]

The infected individual isn't susceptible because he or she is already infected. Other than that individual, the rest of the population is susceptible.

I don't see the point of emphasizing that, but that's what "otherwise" tells us.

 

[emsr2d2]

I can see what they were trying to do but, as SoothingDave said, I would expect the part after "an otherwise" to be contrary to the part before it.

... one infected individual in an otherwise uninfected population ...

 

[SoothingDave]

The infected individual isn't susceptible because he or she is already infected. Other than that individual, the rest of the population is susceptible.

I don't see the point of emphasizing that, but that's what "otherwise" tells us.

I was wondering if there was some medical definition that "susceptibility" ended once one was infected. The word "otherwise" certainly doesn't add any information here.

 

[emsr2d2]

Given that the latest research seems to indicate that antibodies wane very quickly after recovering (I assume we're talking about Covid-19), it looks as if people will return to being susceptible. If the research continues to show this, the whole herd immunity idea goes out the window!