JONESBORO — As COVID-19 infections rose by 86.6 percent last week in Craighead County, more people sought vaccinations, an examination of data from the Arkansas Department of Health revealed.

As of Monday, 453 more people had received their first dose and 247 became fully vaccinated against the disease caused by the coronavirus compared to the week earlier.

That brings to 42.26 percent of the county’s population 12 and older who’ve received at least one shot. Still, that’s almost 8 percent below the state average and 14 percent below the 56.1 percent nationally who are at least partially vaccinated.

Only about 500 people received a dose in each of the previous two weeks, according to the figures.

In the first 19 days of July, 2,437 Craighead County residents became infected with the virus. In June, the county recorded only 212 new cases. Active cases grew from 118 on July 1 to 365 on Monday.

In Greene County, 397 received vaccinations last week, compared to 249 in the previous week and 213 the week before that. Lawrence County residents also stepped up their game last week, with 175 people receiving at least their first dose, compared to 83 the previous week and 74 the week before.

While infections escalated in most counties, they slowed somewhat in Poinsett, Jackson and Randolph counties. However, Poinsett County recorded two deaths in the previous seven days, while Greene and Cross counties had one death each.

The nationwide surge in new cases is blamed on the delta variant of the coronavirus, which health officials say accounts for an estimated 83 percent of U.S. COVID-19 cases.

That’s a dramatic increase from the week of July 3, when the variant accounted for about 50 percent of genetically sequenced coronavirus cases.

“The best way to prevent the spread of COVID-19 variants is to prevent the spread of disease, and vaccination is the most powerful tool we have,” said Dr. Rochelle Walensky, director if the Centers for Disease Control and Prevention, during a U.S. Senate hearing Tuesday.

The delta variant is a mutated coronavirus that spreads more easily than other versions. It was first detected in India but now has been identified around the world.

Northeast Arkansas COVID-19 cases by county July 13 through Monday:

Craighead – 227 new cases (86, 61 percent, more than last week); 365 active cases (147 more); deaths, 187 (unchanged).

Greene – 76 new cases (increase of 6, 8.6 percent) 134 active (increase of 16); deaths, 80 (increase of 1).

Lawrence – 29 new cases (increase of 8, 38.1 percent); 49 active (increase of 16; deaths, 43 (unchanged).

Poinsett – 37 new cases (decrease of 2, -5.1 percent); 69 active (reduction of 1); deaths, 80 (increase of 2).

Mississippi – 28 new cases (increase of 7, 33.3 percent); 45 active cases (increase of 12); deaths 110 (unchanged).

Jackson – 18 new cases (decrease of 15, -45.4 percent); 31 active cases (increase of 2); deaths, 38 (unchanged).

Randolph – 18 new cases (reduction of 8, -30.1 percent), 45 active cases (increase of 14); deaths, 48 (unchanged).

Cross – 29 new cases (increase of 17, 141.7 percent), 41 active cases (increase of 26); deaths, 53 (increase of 1).

Clay – 43 new cases (increase of 35, 437.5 percent); 49 active cases (decrease of 4); deaths, 52 (unchanged).

Figures for full and partial vaccinations of persons age 12 and older in Northeast Arkansas as of Monday:

Craighead – 30,582 (33.3 percent), 8,206 (8.94 percent).

Clay – 4,487 (35.77 percent), 586 (4.67 percent).

Cross – 5,185 (37.27 percent), 1,024 (7.36 percent).

Greene – 12,630 (33.13 percent), 2,3901 (6.27 percent).

Jackson – 4,225 (29.14 percent), 789 (5.44 percent).

Lawrence – 4,478 (31.87 percent), 1,048 (7.46 percent).

Mississippi – 9,787 (29.06 percent), 1,895 (5.63 percent).

Poinsett – 6,068 (30.63 percent), 1,578 (7.97 percent).

Randolph – 3,737 (24.67 percent), 1,317 (8.7 percent).

Hospitalizations due to COVID-19 rose statewide from 255 to 787 in the past week.

The Associated Press contributed to this report.