CNN  — 

People who live in rural areas have an increased risk of hospitalization and death from Covid-19, yet as of April, the vaccination rate in rural areas lagged behind cities – and that could hinder the end of the pandemic, according to a new report from the US Centers for Disease Control and Prevention.

As of Monday, about 60% of people 18 and older have had at least one Covid-19 vaccine in the US, according to CDC Director Dr. Rochelle Walensky – a “landmark day,” she said. But scientists estimate the country will need 70% and 85% of the US population to be vaccinated to reach herd immunity and rural America is lagging far behind.

Through April 10 of this year, vaccination coverage was nearly 39% in rural counties, compared to more than 46% in urban counties, according to the CDC’s Morbidity and Mortality Weekly Report, published Tuesday. That was true for counties across the country, and across all age groups, and among men and women. Yet, in September, the incidence of Covid-19 in rural counties surpassed those in urban counties.

Getting a vaccine to people in rural areas can be difficult. Nearly 80% of rural Americans live in areas that are designated as “medically underserved” by the US government. Easy access to a doctor for regular appointments is difficult in many parts of the country.

There’s also the issue of hesitancy.

In April, a survey by the Kaiser Family Foundation showed persistent resistance to Covid-19 vaccination in rural America. Some 3 in 10 residents said they would “definitely not” get a Covid-19 vaccine or they would get one only if someone required they have it. That’s a higher percentage than in urban or suburban areas.

People who live in these rural areas, however, are more vulnerable to severe Covid-19, in part, because of the lack of access to care and, because, in general, more people in these areas have underlying health conditions, and fewer people are insured.

The trend over the last century has been for people to move to big cities, yet about 60 million people live in rural counties – a fifth of the US population. If this low vaccination rate continues, this could have a negative impact on the country’s overall efforts to control Covid-19.

“Because residents of rural communities are at increased risk for severe COVID-19-associated illness and death, vaccination disparities between urban and rural areas might hinder efforts to reduce morbidity and mortality from COVID-19 nationally,” the report said.

The CDC recommends that public health leaders collaborate with doctors and local influencers in rural areas to address hesitancy, to ensure equitable vaccine access, and to encourage more people to get the Covid-19 vaccine.

“We remain committed to listening and to reaching out to communities in every corner of the United States and our work to narrow these differences and make sure that vaccine coverage is equitable regardless of whether you live in rural or urban areas,” Walensky said.

Walensky said it will be important to “meet people where they are, wherever they are.” One example she gave was the federal government’s vaccination and testing effort in partnership with the Alabama Department of Public Health and the Alabama National Guard at Talladega Superspeedway.

Other efforts to meet people where they are with vaccines have seemed to make a difference, according to White House COVID-19 Response Team senior adviser Dr. Marcella Nunez-Smith.

Through the Biden administration’s push to get more FEMA-run federal vaccination sites online, and get vaccines to the federal government’s community health centers, more people of color have gotten access, and it has paid off.

Get CNN Health's weekly newsletter

Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.

In the past two weeks, 51% of those vaccinated in the US were people of color – and that’s above the 40% general population representation for these groups.

“We recognize ZIP code is a stronger predictor of health,” Nunez-Smith said at the White House coronavirus briefing on Tuesday. “We know we must push further, and to do so, we have to make sure we reach everyone in this phase.”