(WHTM) — On Dec. 12, 2021, the number of deaths related to COVID-19 in the United States reached 800,000. This came just before the one-year anniversary of the first COVID-19 vaccine given in the U.S. That first shot was given to New York City nurse Sandra Lindsay on Dec. 14, 2020.

From the first case of COVID-19 detected in the U.S. to a rising death toll to major vaccine developments, here is a timeline of COVID-19 milestones both around the country and in Pennsylvania.

On January 20, 2020, the CDC confirmed the first case of COVID-19 in the U.S. from samples taken in Washington state. Pennsylvania’s first “presumptive positive” COVID-19 cases came in March.

In May of 2020, experts estimated that 100,000 Americans had died from COVID-19 — more than died from the Vietnam and Korea wars combined.

By the end of the day on Nov. 24, 2020, an additional 144 deaths attributed to COVID-19 brought Pennsylvania’s death toll related to the virus to 10,000. That number doubled over the next two months for more than 20,000 deaths attributed to the virus by the end of the day on Jan. 20, 2021.

The first coronavirus shot given in the U.S. went into the arm of New York City nurse Sandra Lindsay on Dec. 14, 2020.

On Jan. 19, 2021, almost a year after the first coronavirus case was reported in the U.S., the country surpassed 400,000 deaths attributed to COVID-19. It took less than five weeks for the death toll to go from 300,000 to 400,000.

The FDA gave emergency use authorization for the Pfizer COVID-19 vaccine to be given to adolescents who are 12 to 15 years old on May 12, 2021.

On Aug. 6, 2021, 50% of the entire U.S. population was fully vaccinated against COVID-19. Gov. Tom Wolf tweeted on Aug. 16 that more than 80% of Pennsylvania adults had received at least one dose of the COVID-19 vaccines. At that time, 63.43% of Pennsylvania adults were fully vaccinated.

After the number of daily deaths attributed to COVID-19 decreased during the warmer months, it started climbing again heading into the fall. Pennsylvania’s death toll surpassed 30,000 deaths associated with COVID-19 in October of 2021.

U.S. health officials approved a kid-sized dose of the Pfizer COVID-19 vaccine for children ages 5 to 11 on Nov. 2, 2021.

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After initially opening up booster shots to individuals meeting certain criteria, the FDA made COVID-19 boosters available to anyone 18 or older on Nov. 19, 2021.

The number of U.S. deaths associated with COVID-19 reached 800,000 on Dec. 12, 2021. That’s more than twice the population of Pittsburgh.

In 2021, more than 450,000 people in the U.S. died after contracting the virus up to Dec. 12.