One year of COVID-19 vaccines: Millions inoculated, but hundreds of thousands still lost

Over the last year, an average 1.3 million shots – including first, second, and third doses – have been administered every day.

One year ago, on Dec. 14, 2020, Sandra Lindsay, an intensive care nurse from Northwell Health, became the first American to roll up her sleeve and receive a COVID-19 vaccine, following the green light from federal authorities.

"That day, when that needle pierced my arm, all I felt was this huge boulder, this weight just roll off my shoulders. I'm always optimistic, but my light got even brighter that day," Lindsay told ABC News.

Lindsay's image rapidly circulated across the country, a symbolic representation of the light at the end of the tunnel after the pandemic had forced families apart, shuttered businesses and schools and confined millions of Americans to their homes.

"I just felt hopeful for myself, for the entire country, for the world -- that yes, the day that we've waited so long for healing is coming," Lindsay said.