The head of the World Health Organization said Monday that allowing the coronavirus to spread in an attempt to reach herd immunity was “simply unethical.”
Saying that there had been “some discussion” about the concept recently, WHO Director General Tedros Adhanom Ghebreyesus told reporters that allowing people to be exposed to a deadly virus whose effects are still not fully known was “not an option.”
“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic,” he said at a Monday briefing. “It is scientifically and ethically problematic.”
Typically, “herd immunity” describes a scenario where a large enough share of the population has been vaccinated against a disease to prevent it from spreading widely, allowing the minority of people who have not been vaccinated to be protected by default. But since no vaccine is available for the coronavirus, achieving herd immunity would theoretically require a large number of people to contract the virus.
But among the many unknown factors is whether herd immunity is even possible, Tedros said. “Most people who are infected with the virus that causes covid-19 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,” he said, noting that there are multiple documented instances of people being infected for a second time after recovering from covid-19.
Antibody studies suggest that less than 10 percent of people in most countries have contracted the coronavirus, Tedros said — nowhere near the majority that would be needed for herd immunity. With the “vast majority” of the world’s population susceptible, letting the virus spread “means allowing unnecessary infections, suffering and death,” he said.