WASHINGTON – The U.S. is turning the corner on the most recent surge in COVID-19 cases and more people need to get vaccinated to keep infections on a declining trend, infectious disease specialist Anthony Fauci said.

Fauci, who is President Joe Biden’s chief medical adviser, said that while the full vaccination rate has reached 55%, the key risk is the 70 million eligible people in the U.S. who haven’t gotten a shot.

“We certainly are turning the corner on this particular surge,” Fauci said on ABC’s “This Week” on Sunday. “The way to keep it down, to make that turnaround continue to go down, is to do what we mentioned: get vaccinated.”

Study results showing that a Merck & Co. experimental pill slashed the risk of getting seriously ill or dying from COVID-19 are “very impressive,” Fauci said on CNN’s “State of the Union.”

“So we really look forward to the implementation of this and to its effect on people who are infected,” he said. The pill is a “big deal,” he said on ABC.

Merck agreed in June to a $1.2 billion deal with the U.S. government to supply 1.7 million courses of the treatment, which raises the possibility that many virus patients could be treated before reaching the hospital. Fauci said the government has “the option for millions more.”

“And now that we have this success, the company certainly is going to rev up and make tens and tens of millions more for the rest of the world and for us,” he said on CBS’s “Face the Nation.”

U.S. deaths since the start of the pandemic surpassed 700,000 last week in what Biden called an “astonishing death toll” that’s “yet another reminder of just how important it is to get vaccinated.”

Fauci dismissed attempts to blame immigrants and tourists as a major source of the spread of COVID in the U.S., a belief held by 37% of Americans overall and 55% of Republicans, according to a recent poll by the Kaiser Family Foundation.

“If you just look at the data and look at the people who have gotten infected, look at the people who are in the hospital, look at the people who died – this is not driven by immigrants,” Fauci said on CNN’s “State of the Union.” “This is a problem within our country, the same way it’s a problem with other countries throughout the world.”

He declined to weigh in on whether he saw a medical reason for the Centers for Disease Control and Prevention to continue imposing a rule that makes it easier to expel migrants due to the pandemic.

“My feeling has always been that focusing on immigrants, expelling them or what have you, is not the solution to an outbreak,” he said.