It's been three years since COVID-19 was first detected in the U.S. On Jan. 20, 2020, a man in Washington tested positive for the virus after returning from Wuhan, China.
At the time, the Centers for Disease Control and Prevention said it still wasn't clear how easily the virus could spread from person to person.
"The confirmation that some limited person-to-person spread with this virus is occurring in Asia raises the level of concern about this virus, but CDC continues to believe the risk of 2019-nCoV to the American public at large remains low at this time," the CDC said in a Jan. 21, 2020, press release.
The situation would rapidly evolve with the World Health Organization declaring a pandemic on March 11, 2020.
Nearly three years later, the world is still dealing with COVID-19. However, vaccines have been made available to help slow the spread and prevent severe illness and death.
The U.S. has reported more than 100 million cases of COVID-19. The virus has contributed to more than 1 million deaths in the country, according to the CDC.
Approximately 70% of the U.S. is fully vaccinated against the virus. However, fewer people are choosing to get their booster shot. The CDC says only 15% of the U.S. population is boosted.