World Health Organisation Director-General Dr Tedros Adhanom Ghebreyesus said the idea of fighting a rapidly spreading pandemic like Covid-19 by developing herd community by trying to spread the virus among people is "unethical" and cannot be justified scientifically.
The WHO chief argued that we cannot justify herd community as a strategy to respond to an outbreak, especially a pandemic like Coronavirus. Speaking on the same, he said there has been some discussion on the concept of reaching the "so-called herd immunity" by making the virus spread among people.
He said instead of focusing on herd immunity, "We must prevent amplifying events, protect the vulnerable, empower and educate communities and find, isolate, test and treat (patients).
What is herd immunity?
Dr Tedros said herd community is a concept that is used for vaccination in which a population can be protected from a certain virus if we can reach the onset of a vaccination.
"For example, herd immunity against measles requires about 95 per cent of a population to be vaccinated. The remaining 5 per cent will be protected by the fact that measles will not spread among those who are vaccinated. For polio, the threshold is about 80 per cent. In other words, herd immunity is achieved by protecting people from a virus, not by exposing them to it," he said.
WHO chief has opposed the idea of herd community and said this strategy has never been used to respond to an outbreak.
Herd community is Scientifically and ethically problematic
WHO Chief said, "Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic. It is scientifically and ethically problematic.”
Further explaining why the herding community is not a reasonable concept, Dr Tedros said herd immunity is problematic also because we still don't know how our immune system responds to Covid-19.
Herd immunity and Covid reinfection
Dr Tedros statement comes after the rising confirmed cases of reinfection being reported in five countries, thus raising questions on how strong the antibodies are once a person contracts the virus. Evidence shows that Covid-19 infection does provide some immunity but it is very unclear as to how strong this immunity can be and how long it lasts to protect the person from reinfection.
The latest case of reinfection was reported in Nevada, US where a 25-year-old man got Covid-19 twice in just 48 days, even though he had tested negative on two occasions during this period. Experts said that the man’s second encounter with the virus was "more severe" and he had to be hospitalised and given oxygen support.
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Dr Tedros said, "Most people who are infected with the virus develop an immune response within the first few weeks, but we don't know how strong or lasting that immune response is, or how it differs for different people. There have also been some examples of people infected with Covid-19 being infected for a second time. Seroprevalence surveys suggest that in most countries, less than 10 per cent of the population have been infected with the Covid-19.”
He added that a huge number of people are capable of attracting the virus across countries. So letting the virus circulate unchecked "means allowing unnecessary infections, suffering and death", the WHO chief said.