Fauci warns of risk if too many people refuse coronavirus vaccine

Anthony FauciAnthony FauciTrump adviser knocks Fauci: Wrong about 'everything' Overnight Health Care: Experimental COVID-19 vaccine shows immune response in early results Fauci: Young people have 'societal responsibility' to avoid COVID infection MORE, the nation's top infectious disease expert, said Sunday that he's "cautiously optimistic" that a coronavirus vaccine will be available by the start of 2021, but warned that the U.S. would likely not reach herd immunity if a substantial portion of the population refused to take it. 

Fauci said during an interview with CNN that aired as part of the Aspen Ideas Festival that he would settle for a vaccine that was 70-75 percent effective, noting that it would "bring you to herd immunity level.” But he said that it was "unlikely" the U.S. would be able to quell the outbreak if 30 percent of the population refused to take the vaccine when asked about recent survey results. 

Herd immunity is a situation where a sufficient segment of the population is immune to an infectious disease through vaccine or prior illness, making its spread unlikely, according to the Centers for Disease Control and Prevention.

"That’s one of the reasons why we have to make sure we engage the community as we’re doing now to get … people to understand that we are doing everything we can to show that it’s safe and effective and that it’s good [for] them as individuals and society to take the vaccine," Fauci said. "We have a lot of work to do."

Fauci, a key member of the White House coronavirus task force, added that "there is a general anti-science, anti-authority, anti-vaccine feeling among some people in this country — an alarmingly large percentage of people, relatively speaking."

Some polls have shown that a segment of Americans are hesitant about receiving a coronavirus vaccine, even if it were free or of low cost to them.

A CNN survey from May found that about a third of Americans would not try to get a vaccine if it was widely available and cheap. A Washington Post survey released in early June also found that 15 percent of Americans say they would definitely not get a vaccine, even if it was free and widely available to anyone. An additional 12 percent said they probably would not get a vaccine. 

As of Monday, the U.S. had reported more than 2.5 million cases of COVID-19, with more than 125,000 deaths. In recent weeks, parts of the country have experienced surges in case counts and hospitalizations stemming from the disease, causing states like Texas and Florida to pause reopening plans and close bars. 

The World Health Organization said in April that clinical trials had begun for three vaccines, with more than 70 in development.  

Fauci has repeatedly voiced caution while talking about the development of vaccines. He told The Hill in May that "any time you develop a vaccine, you always remember, you always have a question that you may not get an effective vaccine."

"Even if you do everything right and you do everything on time, there's no guarantee you're going to have an effective vaccine. So when we talk about having a vaccine that might be available in December or January, that's assuming that the vaccine is actually effective," he said.