The head of the World Health Organization warned Monday against suggestions by some to just allowto spread in the hope of achieving so-called , saying this was "unethical."
"Herd immunity is achieved by protecting people from a virus, not by exposing them to it," Tedros Adhanom Ghebreyesus said during a virtual press briefing. He explained that "herd immunity is a concept used for vaccination, in which a population can be protected from a certain virus if a threshold of vaccination is reached."
He pointed out that for measles, for example, it is estimated that if 95% of the, the remaining 5% will also be protected from the spread of the virus. For polio, the threshold is estimated at 80%. Herd immunity helps protect vulnerable people like infants and those with compromised immune systems who can't get the vaccine.
However, Tedros 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."
According to Johns Hopkins University, 70% to 90% of Americans would need to have coronavirus antibodies for herd immunity to be achieved. But the nation isyet, even though more than 8 million people have tested positive and 214,000 have died since the pandemic began.
Even as early as April, months before any clinical trials., it's unclear how many people would immediately receive it. Vaccine opponents had already begun efforts to disparage a future vaccine
A mid-May poll conducted by the Associated Press and the University of Chicago found that only about half of Americans said they would get a COVID-19 vaccine, and nearly one-third weren't sure. About 1 in 5 people said they would refuse.
COVID-19 has killed well over one million people and has infected more than 37 million since it first surfaced in China late last year.
Relying on naturally obtaining herd immunity in such a situation would be "scientifically and ethically problematic," Tedros said. "Allowing a dangerous virus that we don't fully understand to run free is simply unethical. It's not an option."
He pointed out that doctors still have a lot to learn about the development of immunity to COVID-19, including how strong the immune response is and how long antibodies remain in the body.
He also noted that it's been estimated less than 10% of the population in most countries are believed to have contracted the disease.
"The vast majority of people in most countries remain susceptible to this virus," he said.