How Herd Immunity Is Supposed to Work: Pretty Cool — If It Works

This three-minute video explains how vaccination works to protect a population, even when many, perhaps most, are not vaccinated.



The same logic applies in the case of naturally acquired immunity within a population.

Here's the explanation of the UK Government's policy in response to the bat flu, as provided by Guido Fawkes:

The government’s internationally unique strategy is premised on the idea that the majority of us will inevitably get the coronavirus and for most of us it will be merely an unpleasant experience from which we will recover. Letting the healthy get it, with the more vulnerable kept physically separated from the majority, in the expectation Britons will develop herd immunity and because immune people cannot infect others. [Thus], in the long run, [there will be fewer] fatalities.

The British Government policy reponse to COVID19 benefits from the Chinese experience. What that experience shows is that the virus-caused demand for hospital care and mortality rises sharply with age, doing so strongly over the age of 60. The UK response reflects this fact.

Thus, the authorities are allowing the infection to spread throughout the population to the point it impacts a substantial number of the elderly. At that point, the elderly will be required to go into quarantine for four months for their own protection.

Quarantining the elderly will have two effects:

(1) it will prevent mass infection of those most liable to life-threatening disease symptoms, thereby limiting both mortality and demand for hospital care;

(2) it will reduce the average number of people each infected person will infect, i.e., the reproduction rate or R_nought. The latter effect, combined with the rise in the proportion of the under-65 population who by then will have acquired immunity, will drive the reproduction rate down, hopefully below 1.0, at which point the epidemic will die out.

Perhaps Britain's current crop of bureaucrats and government advisers are smarter than the old guard:



But: Did they get the timing wrong?

Related:
Buzzfeed: The UK Only Realised "In The Last Few Days" That Its Coronavirus Strategy Would "Likely Result In Hundreds of Thousands of Deaths"
Business Insider: People over 70 in the UK will be quarantined at home for 4 months in a 'wartime' effort to tackle coronavirus