In this Thursday, Jan. 23, 2020, file photo, a patient receives an influenza vaccine in Mesquite, Texas. Credit: LM Otero / AP

About three-quarters of Maine’s eligible population is fully vaccinated against the coronavirus, but four counties remain below two-thirds.

Franklin, Oxford, Piscataquis and Somerset counties remain below that threshold, according to data provided by the office of Democratic Gov. Janet Mills. Somerset County has the lowest percentage in the state, at a little less than 61 percent.

The state’s immunization rates reflect a divide between urban and rural Maine. The four counties with lagging rates are largely rural. Cumberland County, which is the location of Portland and is the most urban county in the state, is above 85 percent vaccinated.

State health officials have said they are working to improve access to vaccinations and testing in rural parts of the state.

Maine as a whole has one of the highest COVID-19 vaccination rates in the country. Mills said Tuesday that a million people in the state have received at least one shot of COVID-19 vaccine. The state’s population is about 1.3 million.

“That such a significant number of folks have gotten vaccinated is a testament to the willingness of Maine people to step up and do what’s right for themselves, their neighbors, and their communities,” Mills said Tuesday.

Still, cases of the virus in Maine have continued to rise in recent weeks. The seven-day rolling average of daily new cases in Maine has risen over the past two weeks from 480.71 on Sept. 20 to 597.3 on Oct. 4.

The AP is using data collected by Johns Hopkins University Center for Systems Science and Engineering to measure outbreak caseloads and deaths across the United States.

Maine public health officials have said the state has been the site of 1,045 deaths and more than 92,000 cases of the virus since the beginning of the pandemic.