The U.S. COVID-19 vaccination program has gone from zero to 50% in less than six months. As of Tuesday afternoon, the Biden administration said, half of the country's adults are now fully vaccinated against the coronavirus. … Nearly 130 million people age 18 and older have completed their vaccine regimens since the first doses were administered to the public in December, the CDC said. Another 70 million vaccine doses are currently in the distribution pipeline, according to the agency.