Herd immunity was really Cummings strategy, then Italy changed everyone's minds:
(Times paywall) Inside No 10 How Boris Johnson changed his priorities: save lives first, and then salvage the economy
https://www.thetimes.co.uk/article/coronavirus-ten-days-that-shook-britain-and-changed-the-nation-for-ever-spz6sc9vb
.....Dominic Cummings, the prime minister’s senior aide,
became convinced that Britain would be better able to resist a lethal second wave of the disease next winter
if Whitty’s prediction that 60% to 80% of the population became infected was right and the UK developed “herd immunity”.
At a private engagement at the end of February, Cummings outlined the government’s strategy.
Those present say it was “herd immunity, protect the economy and if that means some pensioners die, too bad”.
At the Sage meeting on March 12, a moment now dubbed the “Domoscene conversion”,
Cummings changed his mind.
In this “penny-drop moment”, he realised he had helped set a course for catastrophe.
Until this point, the rise in British infections had been below the European average.
Now they were above it and on course to emulate Italy, where the picture was bleak.
A minister said: “Seeing what was happening in Italy was the galvanising force across government.”
By Friday, March 13, Cummings had become the most outspoken advocate of a tough crackdown.
“Dominic himself had a conversion,”
a senior Tory said.
“He’s gone from ‘herd immunity and let the old people die’,
to
‘let’s shut down the country and the economy.’”
.......
Johnson had also been queasy about the previous original approach.
“Boris hated the language of ‘herd immunity’ because it implied that it was OK for people to die,”
a senior source said.
.....
The two experts, together with Hancock and Cummings, all delivered to Johnson one message:
“Now is the moment to act.”
The prime minister agreed:
“We must work around the clock and take all necessary measures.”
One of those present said:
“The mood in the room was astonishing.
You could tell that something very significant had shifted.”