- Dr Anthony Fauci warned that there is a rise in US cases of coronavirus.
- He said that unvaccinated people are mainly being infected.
- The Delta variant spreads most efficiently.
Top US infectious disease expert Dr Anthony Fauci has said the United States is moving "in the wrong direction" in its battle against the coronavirus, as the country has seen a recent rise in infections particularly in states with low vaccination rates.
In an interview on CNN's programme on Sunday, Fauci said many vulnerable people across the US remain unvaccinated - and they are the ones who are spurring the increase in Covid-19 cases.
"We're going in the wrong direction," Fauci said.
"If you look at the inflection of the curve of new infections... it is among the unvaccinated and since we have 50% of the country is not fully vaccinated, that's a problem - particularly when you have a variant like Delta which has this extraordinary characteristic of being able to spread very efficiently and very easily from person to person."
Coronavirus vaccines are widely available across the US, and just less than 60% of adults are fully vaccinated with 68.8% of adults having received at least one dose, according to US Centres for Disease Control and Prevention (CDC) data.
But millions of people have not been vaccinated, and the administration of US President Joe Biden is urging Americans to get their jabs - especially in states where cases have risen in recent weeks.
The sharpest increases in Covid-19 infections are in places with lower vaccination rates. Florida, Texas and Missouri account for 40% of all new cases nationwide, with about one in five of all new cases occurring in Florida, White House adviser Jeffrey Zients said last week.
"If you are vaccinated, the vaccine is highly protective against the Delta variant, particularly against severe disease leading to hospitalisation and sometimes ultimately to death," Fauci said on Sunday.
"It's really an outbreak among the unvaccinated... which is the reason why we're out there practically pleading with the unvaccinated people to go out and get vaccinated."
Fauci said recommending that the vaccinated wear masks is "under active consideration" by the government's leading public health officials, while booster shots may be suggested for people with suppressed immune systems who have been vaccinated.
Fauci, who also serves as Biden's chief medical adviser, said he has taken part in conversations about altering the mask guidelines.
He noted that some local jurisdictions where infection rates are surging, such as Los Angeles County, are already calling on individuals to wear masks in public regardless of vaccination status, a step that he said was in line with CDC recommendations.
The top public health official in Washington state's most populous county, Dr Jeff Duchin, on Friday also asked everyone to wear masks in indoor public spaces - even if they are vaccinated - due to the rise of the Delta variant.