The US is heading "in the wrong direction" on the pandemic as infections surge among the unvaccinated, the country's top infectious disease expert has warned.
Dr Anthony Fauci, the chief medical adviser to US President Joe Biden, says the Delta variant is driving the spike in areas with low vaccination rates.
The coronavirus situation in the country is becoming "a pandemic among the unvaccinated", he told broadcaster CNN on Sunday.
He said US health officials were considering revising mask guidance for vaccinated Americans to curb cases and that offering booster jabs to vulnerable people was also under review.
