World Health Organization warned against the idea that herd immunity might be a realistic strategy to stop the cOVID-19 pandemic.
At a media briefing in London, WHO Director-General Tedros Adhanom Ghebreyesus said, such proposals as simply unethical.
He said, health officials typically aim to achieve herd immunity by vaccination.
WHO chief noted that to obtain herd immunity from a highly infectious disease such as measles, for example, about 95 per cent of the population must be immunized.
He said, herd immunity is achieved by protecting people from a virus, not by exposing them to it.
Some researchers have argued that allowing COVID-19 to spread in populations that are not obviously vulnerable will help build up herd immunity and is a more realistic way to stop the pandemic.
WHO chief said that too little is known about immunity to COVID-19 to know if herd immunity is even achievable.
WHO estimates less than 10 per cent of the population has any immunity to the coronavirus, meaning the vast majority of the world remains susceptible.
He also noted that countries have reported record-high daily figures of COVID-19 to the UN health agency for the last four days, citing surges in Europe and the Americas in particular.