On Sunday, the United States saw the lowest level of Covid-19 cases in nearly a year as vaccination rates climb nationwide. But one group is still seeing high rates of Covid-19 cases and deaths: the unvaccinated.

Is America's coronavirus future 'good,' 'bad,' or 'ugly'? It's all three.

Covid-19 cases drop nationwide

As of Sunday, the seven-day average of new Covid-19 cases is around 26,000, according to Johns Hopkins University (JHU).

Radio Advisory episode: Vaccinating the globe, the ultimate systemness challenge

CDC Director Rochelle Walensky said that case rates haven't been that low since June 18, 2020. "As each week passes and as we continue to see progress, [this] data give[s] me hope," she said.

Eric Topol from the Scripps Research Translational Institute noted that the share of coronavirus tests returning positive results has dropped below 3% for the first time since widespread testing was started, and the number of patients hospitalized with Covid-19 has dropped to its lowest level in 11 months.

Scott Gottlieb, former FDA commissioner, said he believes that "by June, we're probably going to be at one infection per a hundred thousand people per day, which is a very low level."

Meanwhile, the seven-day daily average of Covid-19 deaths has dropped by 23% compared to a month ago, according to JHU's data.

The declines in Covid-19 cases and deaths are coming as more Americans are getting vaccinated. According to CDC, 49.2% of the U.S. population has received at least one dose of a Covid-19 vaccine, while 39.2% have received all doses required in their vaccination course. Meanwhile, 61.3% of American adults have received at least one shot, while 49.6% have received all required doses. In at least 25 states and Washington, D.C., more than half of their adults have received all required doses.

"Across the country, cases of Covid-19, serious illness, and loss of life are all down dramatically," Andy Slavitt, the White House's senior Covid-19 adviser, said. "And they can be brought down even further and the risk of a future wave in your community significantly reduced if we keep up the pace of vaccinations."

Your top resources for Covid-19 readiness

"The people who are getting infected now tend to be people who are younger, less vulnerable to the infection, because a lot of the vulnerable population has been vaccinated," Gottlieb said.

Covid-19 cases remain high among the unvaccinated

But while national Covid-19 case and death rates are painting a favorable picture of the United States' fight against Covid-19, case rates and death rates among the unvaccinated remain high, according to the Washington Post.

The rate of Covid-19 cases among the unvaccinated is 69% higher than the standard national rates, according to the Post, though it is declining. Meanwhile, the death rate among the unvaccinated is about the same as it was two months ago, and the hospitalization rate is as high as it was three months ago.

Unvaccinated people "think it's safe to take off the mask. It's not," Lynn Goldman, dean of the Milken Institute School of Public Health at George Washington University, said. "It looks like fewer numbers, looks like it's getting better, but it's not necessarily better for those who aren't vaccinated."

"Things are getting safer for those who are vaccinated," Umair Shah, Washington's secretary of health, said. "For those who are unvaccinated, they remain at risk. We have to make sure that nuanced message is getting to our community."

Shah said he hopes "this does not become a tale of two societies. The people who are vaccinated and are protected can resume their lives, taking off their masks."

However, the unvaccinated in some cases "are the ones who are not wearing a mask or washing their hands," Shah said. "Those are the very people who oftentimes will socialize and be around similar like-minded people. You're going to have the pandemic continue in those clusters" (Repko, CNBC, 5/23; Morales/Paz, New York Times, 5/23; Groves, Associated Press, 5/22; Maxouris, CNN, 5/24; Keating/Shapiro, Washington Post, 5/21).