U.S. COVID-19 numbers are getting better. But where they go from here depends on vaccinations, Fauci says

The rates of U.S. COVID-19 cases, hospitalizations and deaths are improving; an optimistic sign for the future of the pandemic. But with so many Americans still unvaccinated, the numbers could still go back up, Dr. Anthony Fauci said Sunday.

"If we don't do very well in that regard, there's always the danger that there will be enough circulating virus that you can have a stalling of the diminishing of the number of cases and when that happens, as we've seen in the past with other waves that we've been through, there's the danger of resurgence," said Fauci, the director of the National Institute of Allergy and Infectious Disease and chief medical adviser to President Joe Biden, who appeared on Fox News Sunday with Chris Wallace.

Although cases still remain high at an average of more than 85,000 infections a day, they are down by more than 8,000 from the weeks before, according to data from Johns Hopkins University. And deaths are down an average of more than 200 a day from the start of the month.

Progress in the numbers is still threatened, however, by the low rates of vaccination. As of Sunday, 57% of the total population was fully vaccinated against the virus, according to the U.S. Centers for Disease Control and Prevention.

And though health experts do not know exactly what proportion of the population needs to be protected to control the spread of the virus, Fauci has said a vast majority will need to be vaccinated.