Herd immunity ‘dangerous fallacy’

Herd immunity approaches to managing the coronavirus crisis are a "dangerous fallacy unsupported by the scientific evidence", a group of researchers has warned.

Adopting a herd immunity strategy would not end the pandemic but rather result in recurring epidemics, according to an open letter signed by 80 international researchers published by The Lancet.

The authors argue that any strategy relying on immunity from natural infections of Covid-19 is "flawed", adding that uncontrolled transmission in younger people risks ill-health and death across a whole population.

Instead, the letter, referred to by its authors as the John Snow Memorandum, calls for suppression of the virus until there is an effective vaccine. The letter says: "The arrival of a second wave and the realisation of the challenges ahead has led to renewed interest in a so-called herd immunity approach, which suggests allowing a large uncontrolled outbreak in the low-risk population while protecting the vulnerable.

"Proponents suggest this would lead to the development of infection-acquired population immunity in the low-risk population, which will eventually protect the vulnerable.

"This is a dangerous fallacy unsupported by scientific evidence." Speaking in the Commons on Tuesday, Mr Hancock criticised the so-called Great Barrington Declaration, which calls for an easing of lockdown measures in a switch of strategy to a herd immunity approach.