Extent of COVID-19 vaccine waste remains largely unknown

Medical workers give Pfizer's COVID-19 vaccine Friday, March 12, 2021, in Nashville, Tenn. As millions continue to wait their turn for the COVID-19 vaccine, small but steady amounts of the precious doses have gone to waste across the country. It's a heartbreaking reality that experts acknowledged was always likely to occur. (AP Photo/Mark Humphrey)

A woman arrives for her first dose of Pfizer's COVID-19 vaccine Friday, March 12, 2021, in Nashville, Tenn. As millions continue to wait their turn for the COVID-19 vaccine, small but steady amounts of the precious doses have gone to waste across the country. It's a heartbreaking reality that experts acknowledged was always likely to occur. (AP Photo/Mark Humphrey)

NASHVILLE, Tenn. — As millions continue to wait their turn for the COVID-19 vaccine, small but steady amounts of the precious doses have gone to waste across the country.