GENEVA - The World Health Organization chief warned Monday against suggestions by some to just allow COVID-19 to spread in the hope of achieving so-called herd immunity, saying this was "unethical".
Tedros Adhanom Ghebreyesus said during a virtual press briefing 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 for instance that for measles, it is estimated that if 95 percent of the population is vaccinated, the remaining five percent will also be protected from the spread of the virus.
For polio, the threshold is estimated at 80 percent, he said.
"Herd immunity is achieved by protecting people from a virus, not by exposing them to it," 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," he insisted.
The new coronavirus has killed well over one million people and has infected more than 37.5 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 to lacking information on the development of immunity to COVID-19, including how strong the immune response is and how long antibodies remain in the body.
He also pointed out that it has been estimated that less than 10 percent 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.