CNN  — 

The Delta variant of Covid 19 has now been detected in all 50 states and Washington, DC, according to the latest tally from CNN.

The last state to report the variant is South Dakota, which confirmed its first case on Tuesday.

With the more transmissible variant spreading, this puts even more pressure on local and state officials to vaccinate more people.

Dr. Anthony Fauci said Tuesday he’s “very concerned about” the stark disparity between places with low and high vaccination rates. This unfortunately could lead to there soon being “two Americas” – one where most people are vaccinated and another where low vaccination rates could lead to case spikes.

“When you have such a low level of vaccination superimposed upon a variant that has a high degree of efficiency of spread, what you are going to see among undervaccinated regions – be that states, cities or counties – you’re going to see these individual types of blips,” he said. “It’s almost like it’s going to be two Americas.”

Young people – age 18 to 24 – are still a group that officials are trying to get vaccinated. The proportion of young people hospitalized is increasing, according to Dr. Rochelle Walensky, Centers for Disease Control and Prevention director.

Since May, people ages 12 to 29 have accounted for about a third of hospitalizations – a greater proportion than in the past, Walensky said. CDC data shows, however, that vaccination coverage among young adults is improving. Over the past two weeks, the 18-24 age group made up 12.6% of those becoming fully vaccinated, the CDC said.

But spikes in coronavirus cases are “entirely avoidable, entirely preventable” with vaccination, said Fauci, who heads the National Institute of Allergy and Infectious Diseases.

Fauci’s remarks come as the Delta variant, which is more contagious and aggressive, has reached nearly every state and accounted for 26.1% of US Covid-19 cases as of Tuesday, according to the CDC.

“I’m concerned about the Delta variant,” US Surgeon General Dr. Vivek Murthy told CNN on Wednesday. “And I am worried that what we are seeing in terms of a plateauing of cases nationally but also an increase in cases in many small sections of the United States, that that is, in fact, being driven by the Delta variant.”

There is still a lot of virus circulating in the US, and close to 300 people – “just far too many” – are still dying daily from the coronavir