A letter published in The Lancet October 22 by Graham Medley looks at the term which he feels has become layered with political interpretations, label strategies, and feels that they are not clearly defined.
It is hoped that at some time shortly there will be a vaccine against SARS-CoV-2 and this will be used to seek ways of generating herd immunity – that is promoting widespread immunity in the population and reducing transmission so that the epidemic will end without having to vaccinate the whole population.
Herd immunity is a real phenomenon that occurs whether the immunity generated is naturally acquired or vaccine induced. The term has been used for many decades applied to diseases of people, livestock and wildlife. Graham Medley was quoted in an interview on BBC Newsnight at the start of the epidemic on March 12 trying to explain the phenomenon.
At the time, it was clear that the UK was going to experience an epidemic, but it was not clear how that would develop in the coming weeks, months and years.
In that same interview, he said that the better we manage it, the longer it will be. The worst case would be to have an uncontrollable epidemic.
The epidemic is still ongoing and it remains the case that although most people remain susceptible to infection, control of transmission has to be through non-pharmaceutical interventions.
Isolation and quarantine, physical distancing and contact tracing are still required until the transmission is reduced by immunity. Ideally, this immunity will be vaccine induced rather than through transmission of the disease.
There has been increasing suggestion that one option is to simply protect everyone who is at risk of infection and allow the epidemic to spread to those at low risk. This approach is impossible in practice and as my papers on long COVID have shown, would result in a large proportion of the population having chronic symptoms.
The herd immunity, which The London General Practice supports is that by vaccination and looks forward to the day that a successful vaccine is launched.
Dr Paul Ettlinger
The London General Practice