Coronavirus updates: Fauci calls 'herd immunity' declaration 'ridiculous'

Dr. Anthony Fauci, the nation's top expert on the coronavirus pandemic, said the recent rise in COVID-19 infections across the United States is "concerning" as winter nears.

"We have a baseline of daily infections that are approximately 45-50,000 per day," Fauci, director of the National Institute of Allergy and Infectious Diseases and a key member of the White House coronavirus task force, told ABC News chief anchor George Stephanopoulos in an interview Thursday on "Good Morning America."

"The issue is as we enter -- as we are now -- into the cooler season of the fall and ultimately the colder season of the winter," he added, "you don't want to be in that compromised position where your baseline daily infection is high and you are increasing as opposed to going in the other direction."

Dozens of U.S. states are reporting upticks in COVID-19 test positivity rates, which Fauci said "has proven in the past to be a very good prediction of a surge in cases, which ultimately leads to a surge in hospitalizations."

"Then ultimately in some individuals, that obviously will be an increase in deaths," he added. "So we really got to double down on the fundamental public health measures that we talk about every single day, because they can make a difference."

Fauci, who said that his adult daughters won't be spending Thanksgiving with him and his wife this year due to concerns about spreading the virus, urged families to be careful during the upcoming holidays and evaluate both the risks and benefits of gathering indoors.

"It's up to the individuals and the choices they make," he said.

When asked about President Donald Trump's packed campaign rallies, where many supporters are seen without face masks, Fauci said it's "a high-risk endeavor."

"I don't like to be pitted against what the president says, but it's so clear that when you have congregate settings and so many people, when you're in a situation when the community infection rate is there, you can't runaway from or argue with the numbers," he said.

A declaration by a group of scientists calling for an approach that relies on "herd immunity" to defeat the coronavirus pandemic, which has been embraced by the White House, is "ridiculous" and "total nonsense," said Dr. Anthony Fauci, the nation's top expert on infectious diseases.

"That declaration has a couple things in it that I think are fooling people, because it says things that are like apple pie and motherhood," Fauci, director of the National Institute of Allergy and Infectious Diseases and a key member of the White House coronavirus task force, told ABC News chief anchor George Stephanopoulos in an interview Thursday on "Good Morning America."

The so-called Great Barrington Declaration, which claims on its website to have been signed by more than 9,000 medical and public health scientists around the globe, opposes lockdowns and argues that authorities should allow the novel coronavirus to spread among young, healthy individuals while protecting the elderly and the vulnerable.

"If you just let things rip and let the infection go -- no masks, crowd, it doesn't make any difference -- that quite frankly, George, is ridiculous because what that will do is that there will be so many people in the community that you can't shelter, that you can't protect, who are going to get sick and get serious consequences," Fauci said. "So this idea that we have the power to protect the vulnerable is total nonsense, because history has shown that that's not the case. And if you talk to anybody who has any experience in epidemiology and infectious diseases, they will tell you that that is risky and you'll wind up with many more infections of vulnerable people, which will lead to hospitalizations and deaths. So I think that we just got to look that square in the eye and say it's nonsense."

During a briefing Monday, World Health Organization director-general Tedros Adhanom Ghebreyesus called herd immunity "scientifically and ethically problematic.

"Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic," Tedros said.

The U.K. government is expected to impose new restrictions in London as part of efforts to stop the rapid spread of the novel coronavirus.

Under England's new three-tier system of local COVID-19 alert levels, the British capital is expected to move up a level from "medium" -- the first tier -- to "high" -- the second tier -- at midnight on Friday. That means people from different households will no longer be allowed to meet indoors, including in homes, pubs and restaurants. Groups of no more than six people from different households can still meet outdoors.

Pubs and restaurants across London will continue to be allowed to stay open until 10 p.m.

London Mayor Sadiq Khan said the new measures are "deemed to be necessary in order to protect Londoners" but that he believes action is also needed "on a national scale," such as implementing a two-week lockdown. He said the city will soon reach an average of 100 COVID-19 cases per 100,000 population, a level some parts of England have already surpassed.

"I must warn Londoners that we've got a difficult winter ahead," Khan said in a televised statement Thursday. "But just as we've always done through our city's great history, I know that we’ll get through this dark time by pulling together."

The move comes as England saw its number of infections quadruple in the last three weeks. There are now more patients hospitalized with COVID-19 than when the country went into lockdown in late March, according to British Prime Minister Boris Johnson.

ABC News' Guy Davies contributed to this report.

Russia registered another 286 deaths from COVID-19 in the last 24 hours, setting a new record for its daily death tolls from the disease.

The country's previous record of 244 fatalities was set earlier this week.

An additional 13,754 new cases of COVID-19 were also confirmed in the past day, down from a peak of 14,231 registered the previous day. It's the first time in seven days that Russia didn't break its own record for single-day case counts.

The cumulative totals now stand at 1,354,163 confirmed cases and 23,491 deaths, according to Russia’s coronavirus response headquarters.

Russia, a country of 145 million people, has the fourth-highest tally of COVID-19 cases in the world, behind only the United States, India and Brazil.

ABC News' Alina Lobzina contributed to this report.