About one-third of Alabama’s counties, including most of the state’s heavily populated areas, are at very high risk for COVID-19 as vaccination rates continue to lag, state statistics showed Monday.

While overall caseloads and hospitalizations remain far below levels when the pandemic was at its worst early this year, the potential for infection remains elevated in areas including Birmingham, Huntsville, Montgomery and much of two regions, the Wiregrass of southeast Alabama and the Tennessee Valley in the north.

Of the state’s most populated areas, only Mobile County on the coast is considered as being at low risk for the illness caused by the new coronavirus, according to the Alabama Department of Public Health. Nearly three dozen rural counties with sparse populations also are at low risk.

The statistics don’t include the July 4 holiday period, so health officials will look to see whether holiday gatherings contribute to a rise in infections later this month.

Only a relative handful of cases involving the fast-spread delta variant of the virus has been confirmed in Alabama, the state health officer, Dr. Scott Harris, told WSFA-TV last week, but the state lacks the ability to do much testing for it.

The fact that so many counties are at very high risk, meaning cases are remaining level or rising, poses “a little bit of concern,” Harris said.

With only about 30% of its roughly 5 million residents fully vaccinated, Alabama trails every state but Mississippi in inoculation rates. Increasing vaccine acceptance could reduce serious illness since statistics from the Alabama Hospital Association show that 94% of patients hospitalized with COVID-19 haven’t been vaccinated.

The illness has killed more than 11,350 people statewide, and more than 550,000 people have tested positive. The hospital group has launched a campaign to encourage vaccinations in hopes of stemming the spread of the virus.