In a milestone moment in the Mile High City, on Nov. 27, Denver Health administered the first live Ebola vaccine for preventative measures to some patients, 9News reported.

In 2015, HHS designated Denver Health one of 13 Regional Emerging Special Pathogens Treatment Centers in the U.S. — serving as an infectious disease training and care hub for six states in its region. 

It is one of the first health systems in the country to administer the vaccine, according to the news outlet. 

The vaccine, Ervebo, was first approved by the FDA in 2019 for anyone older than 1.

While outbreaks have continued across the globe, Ebola is less frequently seen in the U.S. but nonetheless is extremely deadly with a mortality rate between 70% and 90% when left untreated, according to the CDC. 

"Importation of Ebola disease to the United States by an infected traveler from an outbreak area is a recognized risk with the potential for spread to other people," the CDC states. "During the 2014-2016 Ebola disease outbreak in West Africa, 11 people were treated for [Ebola] in the U.S., and two of them died. Nine of these cases were imported into the U.S."