After months of effort to limit the spread of the coronavirus in the United States, herd immunity has emerged as a controversial topic.

During a call with reporters on Monday, White House senior administration officials discussed a controversial declaration written by some scientists that advocates for ending lockdowns, building immunity and pushing for those who are not vulnerable to Covid-19 to resume normal life.

The Great Barrington Declaration aligns “very strongly with what the President has said for months — that is strongly protect the high-risk elderly and vulnerable and open schools and restore society to function,” a senior administration official said during the call.

Yet many experts warn that the idea to allow the novel coronavirus to circulate freely — also known as a “herd immunity” approach — is dangerous.

“Allowing a dangerous virus that we don’t fully understand to run free is simply unethical,” Tedros said during a briefing on Monday. “It’s not an option.”

Tedros explained that herd immunity is a “concept used for vaccination,” not pandemic control.

“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic. It is scientifically and ethically problematic,” Tedros said. “Letting the virus circulate unchecked, therefore, means allowing unnecessary infections, suffering and death.”

Previously, White House Coronavirus Task Force member Dr. Scott Atlas responded to a report in late August that claimed he is a proponent of a “herd immunity” strategy to combat Covid-19. “I’ve never advocated that strategy,” Atlas said at a press conference in Florida.

Such an approach — similar to what was pursued in Sweden — would mean that many people nationwide would have to get sick with the coronavirus in order to build up a natural immunity across communities. As the virus spreads and sickens people, many could die in the process.

Medical reference: CNN Health