How do we think about the UK lockdown debate?

Encyclopedia of Opinion

Question: How do we think about the UK lockdown debate?
Position1 of 5›: The libertarian position, or 'End lockdown now!'
Argument‹6 of 8›: Most people have already had the virus

According to Oxford epidemiologists Sunetra Gupta, 68% of the UK population have already been infected with the virus and are therefore immune. In this case, the lockdown is doing unnecessary harm to our economy and our lives.

The argument

In a paper published by Sunetra Gupta, a professor of theoretical epidemiology at Oxford University, she and her colleagues argue that, based on their model, 68% of people were infected with Covid-19 by mid-March. She also argued, in an interview with The Guardian, that locking down the economy and enacting a mandatory stay-at-home policy is a drastic solution to a problem that does not exist, saying that the cost of a lockdown is far greater than the cost of the virus. Her model suggests that if the virus was present in Britain a month earlier than thought—December rather than January—then cases would skyrocket, but the fatality rate would be a fraction of the 1% it's thought to be. This is the case because of herd immunity, the idea that if a large swath of a population is infected with the disease and then recovers, the likelihood of future infection or death is minimal. Gupta argues for an increase in antibody testing—a test to see whether healthy people have the antibodies to fight off Covid-19, or to show they've been previously infected—is needed to prove her theory, and that she believes current antibody data is inaccurate and outdated. A separate study published by researchers at the University of Manchester argues that by the second week of April, almost 27% of the UK population—16 million people—had already had Covid-19. While the virus is dangerous and wreaked havoc on a predominantly older population, the peak has passed. A one-size-fits-all solution to a lockdown does more harm than good.

Premises

[P1]Proponents cite Oxford epidemiologist Sunetra Gupta's model estimating that 68% of Britons were infected by mid-March, and a University of Manchester study suggesting some 16 million people (27%) had been infected by mid-April, arguing the peak had already passed. [P2] They argue that with so much of the population already exposed and moving toward herd immunity, the true fatality rate is far below 1%, so a mandatory one-size-fits-all lockdown imposes an economic cost greater than the harm of the virus. [C] Because most people have already had the virus and its peak has passed, the libertarian case to end lockdown now is justified.

Counter-arguments

A new study found cases of patients catching Covid-19 twice, so ending the lockdown solely based off of the likelihood that most UK residents have had Covid could result in even more infections. Also, the genetic makeup of Covid-19 is changing, possibly causing the virus to become more contagious. Scientists have not yet figured out if the virus has changed enough to make a second infection more likely, but it's certainly a possibility.

Rejecting the premises

[Rejecting P1] The Oxford paper was an exploratory modelling exercise setting out a range of scenarios under differing assumptions about how many infections go undetected; its authors presented the high figure as one such scenario requiring antibody testing to check, not as an estimate of what had occurred. That testing followed within months, and population antibody surveys found prevalence far below both figures the premise cites. [Rejecting P2] Herd immunity is a threshold effect rather than a gradient, and the arithmetic runs backwards: a large hidden infection count lowers the estimated fatality rate only by enlarging the denominator, which does nothing to reduce the deaths already recorded and nothing to protect those not yet infected. The economic comparison is asserted rather than shown, and the argument's conclusion rests on evidence it openly concedes it does not yet have.