The U.S. could finally have the COVID-19 pandemic under control by next spring—but only if enough Americans get vaccinated before then, according to Dr. Anthony Fauci. President Joe Biden’s chief medical adviser told CNN on Sunday night: “We hope we'll be there... but there’s no guarantee because it’s up to us. If we keep lingering without getting those people vaccinated that should be vaccinated, this thing could linger on and lead to the development of another variant.” Fauci said that it’s not clear what proportion of people had to be vaccinated before life could return to normal, so the only answer was to persuade as many people as possible to get their shots. At the moment, only 51.5 percent of the population are fully vaccinated. Fauci was speaking to CNN after the FDA gave its full approval to the Pfizer-BioNTech vaccine for anyone aged 16 and over.