By R Prasad Published 18 May 2020
The World Health Organisation has condemned the “dangerous” concept of herd immunity for managing the coronavirus pandemic.
Dr Michael Ryan, executive director of the WHO’s health emergencies programme said it was wrong to think that countries can “magically” make their populations immune to Covid-19.
It was reported in March that the UK government was hoping to achieve herd immunity by allowing the virus to make its way through the population. Health secretary Matt Hancock denied it was ever part of government strategy.
Dr Ryan told a press briefing in Geneva: “Humans are not herds, and, as such, the concept of herd immunity is generally reserved for calculating how many people will need to be vaccinated and the population in order to generate that effect.”
The WHO director added: “So I do think this idea that ‘maybe countries who had lax measures and haven’t done anything will all of a sudden magically reach some herd immunity, and so what if we lose a few old people along the way?’ This is a really dangerous, dangerous calculation.”
Herd immunity is an epidemiological concept usually reserved for describing how a population is protected from a disease depending on the levels of people vaccinated.
For instance, when between 90 per cent and 95 per cent of the population is vaccinated against measles, this should be enough to protect others who are unable to get an inoculation – such as babies before they reach the age at which they can be immunised.
Sir David King, the former chief scientific adviser to the UK government suggested at the end of April that ministers could still secretly be seeking to create herd immunity, having “softened” their tests for starting to relax restrictions.
Dr Ryan said he was hopeful that Germany and South Korea would be able to suppress new clusters of the virus and praised their test and tracing surveillance programmes, which he said was key to avoiding large second waves. ( Te Hindu )
