Using the principle of so-called "herd immunity" to stem the COVID-19 pandemic is "unethical" and "not an option" countries should pursue to defeat the virus, the UN health agency chief warned on Monday.
"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", Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization (WHO), told the agency's regular press briefing in Geneva.
But, he explained, it is achieved by protecting people from the virus, "not by exposing them to it".
"Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak", the WHO chief said, calling it "scientifically and ethically problematic".
To obtain herd immunity from measles, for example, about 95 per cent of the population must be vaccinated. However, according to WHO estimates, less than 10 per cent of the global population has any immunity to the coronavirus, leaving the "vast majority" of the world susceptible.
"Letting the virus circulate unchecked, therefore, means allowing unnecessary infections, suffering and death", Tedros said.
Cases on the rise
Tedros noted that in recent days, the world was seeing the most rapid rise in infections during the course of the whole pandemic, especially in Europe and the Americas.
"Each of the last four days has been the highest number of cases reported so far", he stated. "Many cities and countries are also reporting an increase in hospitalizations and intensive care bed occupancy".
The WHO chief also reminded that, as an "uneven pandemic", every country is responding differently, and stressed that outbreaks can be controlled using targeted measures, such as by preventing amplifying events, isolation and testing.
"It's not a choice between letting the virus run free and shutting down our societies" he declared.
Again: 'No silver bullet'
WHO noted that many have harnessed their stay-at-home time to develop plans, train health workers, increase testing time and capacity, and improve patient care.
And digital technologies are helping to make tried-and-tested public health tools even more effective, such as better smartphone apps to support contact tracing efforts.
"We well understand the frustration that many people, communities and Governments are feeling as the pandemic drags on, and as cases rise again", Tedros said.
However, there are "no shortcuts, and no silver bullets", he added.
Only a comprehensive approach, using every tool in the toolbox, has proven effective.
"My message to every country now weighing up its options is: you can do it too."